The effects of driver factors and sign design features on the comprehensibility of traffic signs

Vertical is Beneficial but volume is Irrelevant: Optimization of urban guide signs based on spatial representation of road networks

Urban guide signs, a fundamental component of traffic sign systems, convey both directional and locational information. Previous studies mainly focused on the font or volume of information, while little attention was paid to the layout of text-based Chinese guide signs, which is an unregulated area but crucial in practical applications and related to people's travel safety. This study investigates the impact of text layout and information volume on the spatial representation of road networks through two experimental studies, examining the effects of different designs on path determination and global road network knowledge. The results indicate that the text layout of urban road guide signs significantly influences the formation of spatial representation of the road network. Specifically, vertical guide signs displaying road names on both sides proved more effective than horizontal ones. While the volume of road name information does not markedly affect the formation of spatial representation, the arrangement of road names does influence the determination of information volume, with vertical layouts facilitating the presentation of more information. It is anticipated that these design recommendations for road signs can effectively mitigate the incidence of road traffic accidents.

The Effects of Animation on the Guessability of Universal Healthcare Symbols for Middle-Aged and Older Adults

OBJECTIVE

The purpose of this study was to investigate whether animation can help to improve the comprehension of universal healthcare symbols for middle-aged and older adults.

BACKGROUND

The Hablamos Juntos (HJ) healthcare symbol system is a set of widely used universal healthcare symbols that were developed in the United States. Some studies indicated that HJ healthcare symbols are not well-understood by users in non-English-speaking areas. Other studies found that animations can improve users' comprehension of complex symbols. Thus, we wanted to test whether animation could help to improve users' comprehension of HJ symbols.

METHODS

The participants included 40 middle-aged and 40 older adults in Taiwan. We redesigned the 12 HJ symbols into three visual formats-static, basic animation, and detailed animation-and compared them to find which best improved the participants' guessability scores.

RESULTS

(1) Middle-aged adults' comprehension of static and basic animated symbols was significantly better than that of older adults, but there was no significant difference in the guessability scores between the two age groups in terms of detailed animated symbols; (2) In general, both basic animation and detailed animation significantly improved the guessability score, but the effect with detailed animation was significantly greater than that with basic animation; (3) Older women were more receptive to detailed animation and showed better guessing performance.

CONCLUSION

Detailed animation contains more details and provides a more complete explanation of the concept of the static symbols, helping to improve the comprehension of HJ symbols for middle-aged and older adult users.

APPLICATION

Our findings provide a reference for the possibility of new style symbol design in the digital and aging era, which can be applied to improve symbol comprehension.

How supplementary sign features can improve traffic safety among motorcyclists? The effect of capitalization and information length on road sign comprehension

OBJECTIVES

Supplementary signs are essential to improve riders' understanding of road signs. In order to attract the rider's attention and ensure the information on the supplementary sign is effectively delivered, a study on the effective ways to display the information in the supplementary sign is needed. The current study examined the effects of capitalization and information length in supplementary signs on road sign comprehension among riders.

METHOD

A randomized 2 (capitalization: all letters capitalized vs the first letter capitalized) × 2 (information length: long vs. short) factorial design experiment was conducted on 131 young motorcyclists in the Jakarta area. Road sign comprehension was measured using sign comprehension time and sign comprehension level.

RESULT

A 2 × 2 factorial ANOVA analysis showed a significant effect of information length on sign comprehension time: less information in supplementary signs can increase sign comprehension time. Additionally, a significant interaction was found between capitalization and information length on sign comprehension level: sign comprehension levels would be improved if supplementary signs were presented with capitalization at the beginning of each word and had a long information length.

CONCLUSION

This study suggests that there is a need to consider the capitalization and length of information in designing supplementary traffic signs. The effective design of supplementary signs could help riders to comprehend the road sign quickly and accurately, thus improving traffic safety.

The architecture of functional brain network modulated by driving during adverse weather conditions

Traffic accidents caused by adverse weather conditions have attracted the attention of many countries. Previous studies have focused on the driver's response in a particular situation under foggy conditions, but little is known about the functional brain network (FBN) topology that is modulated by driving in foggy weather, especially when the vehicle encounters cars in the opposite lane. An experiment consisting of two driving tasks is designed and conducted using sixteen participants. Functional connectivity between all pairs of channels for multiple frequency bands is assessed using the phase-locking value (PLV). Based on this, a PLV-weighted network is subsequently generated. The clustering coefficient (C) and the characteristic path length (L) are adopted as measures for the graph analysis. Statistical analyses are performed on graph-derived metrics. The major finding is that the PLV is significantly increased in the delta, theta and beta frequency bands while driving in foggy weather. Additionally, for the brain network topology metric, compared with driving in clear weather, significant increases are observed (driving in foggy weather) in the clustering coefficient for alpha and beta frequency bands and the characteristic path length for all frequency bands considered in this work. Driving in foggy weather would regulate FBN reorganization in different frequency bands. Our findings also suggest that the effects of adverse weather conditions on functional brain networks with a trend toward a more economic but less efficient architecture. Graph theory analysis may be a beneficial tool to further understand the neural mechanisms of driving in adverse weather conditions, which in turn may help to reduce the occurrence of road traffic accidents to some extent.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11571-022-09825-y.

Effects of traffic sign design and personal characteristics on the usability of traffic signs

BACKGROUND: Previous researchers examined the effects of either drivers’ personal characteristics or traffic sign design features on the usability of traffic signs. Their research indicated a connection existed between personal characteristics and usability and between design features and usability. OBJECTIVES: The focus of this study was to investigate which personal characteristics of drivers and which features of traffic sign design affect traffic sign usability the most. METHODS: The study was conducted in three stages. In the first stage, the participants filled out a questionnaire designed to record each driver’s personal characteristics. In the second stage, a System Usability Scale (SUS) was used to evaluate the subjective usability of traffic signs. The SUS had 10 statements that participants (N = 386) scored on a 5-point Likert-type scale from strongly agree to strongly disagree. In the third stage, these participants assigned from 0 to 100 points to 20 signs based on participant perception of the five design features of familiarity, concreteness, simplicity, meaningfulness, and semantic distance. RESULTS: The results showed that four of the five personal characteristics studied (age, education level, possession of a driving license, and formal driving experience) correlated significantly with traffic sign usability. The exception was gender, which did not correlate significantly. Additionally, it was found that the five traffic sign design features correlated in varying degrees of significance with each other and with specific traffic signs. CONCLUSIONS: Traffic sign usability depends mostly both on driver education level and age group and on the design feature of meaningfulness. These findings have implications for how drivers should be trained and how signs should be designed.

Combination Layout of Traffic Signs and Markings of Expressway Tunnel Entrance Sections: A Driving Simulator Study

To determine a better combination of signs and markings on expressway tunnel entrance sections, three types of typical signs and markings were compared and tested according to five indicators: speed, lane lateral offset, lane change behavior, fixation behavior, and operating load, using a driving simulator. The results identified that the obvious no overtaking and speed limit signs, combined with a layer of thin red pavement, had the most influence on drivers’ speed, and they led to the highest fixation frequency of static facilities, the longest average distance from the completion point of the lane change to the entrance, and the longest average lane change distance, which could help drivers to pass through tunnel entrance sections more smoothly. The location of the static facilities should be between 3 s before the tunnel entrance and 3 s after entering the tunnel, as this is the area where a driver’s relative viewpoint changes. The improper combination of warning signs and deceleration measures will affect a driver’s judgment, causing negative effects, such as premature lane changes and an increased operating load. The research results can provide a design basis and reference for the combination setting of safety signs and markings on tunnel entrance sections.

Dynamic Graphical Instructions Result in Improved Attitudes and Decreased Task Completion Time in Human–Robot Co-Working: An Experimental Manufacturing Study

Collaborative robots offer opportunities to increase the sustainability of work and workforces by increasing productivity, quality, and efficiency, whilst removing workers from hazardous, repetitive, and strenuous tasks. They also offer opportunities for increasing accessibility to work, supporting those who may otherwise be disadvantaged through age, ability, gender, or other characteristics. However, to maximise the benefits, employers must overcome negative attitudes toward, and a lack of confidence in, the technology, and must take steps to reduce errors arising from misuse. This study explores how dynamic graphical signage could be employed to address these issues in a manufacturing task. Forty employees from one UK manufacturing company participated in a field experiment to complete a precision pick-and-place task working in conjunction with a collaborative robotic arm. Twenty-one participants completed the task with the support of dynamic graphical signage that provided information about the robot and the activity, while the rest completed the same task with no signage. The presence of the signage improved the completion time of the task as well as reducing negative attitudes towards the robots. Furthermore, participants provided with no signage had worse outcome expectancies as a function of their response time. Our results indicate that the provision of instructional information conveyed through appropriate graphical signage can improve task efficiency and user wellbeing, contributing to greater workforce sustainability. The findings will be of interest for companies introducing collaborative robots as well as those wanting to improve their workforce wellbeing and technology acceptance.

Effects of Semantic Congruence on Sign Identification: An ERP Study

OBJECTIVE

The purpose of this study was to investigate the effects of semantic congruence and incongruence on sign identification by using event-related potentials (ERPs).

BACKGROUND

Sign systems have crucial roles in public spaces and traffic facilities. Poorly designed signs can easily confuse pedestrians and drivers and reduce the efficiency of public activities and urban administration.

METHOD

Thirty-one participants completed a sign identification experiment independently in a laboratory setting. Experimental materials were selected from GB/T 10001, a Chinese national recommendation standard that is officially named Public Information Graphical Symbols for Use on Signs. All ERP data were processed using MATLAB 13b, and behavioral data were analyzed using Stata 14.

RESULTS

N170, P200, N300, and N400 components were induced during semantic processing. Statistical analysis revealed that semantic congruence has a main effect on N300 in the frontal region and has a main effect on N400 at FZ in the frontal region, CPZ in the parietal-central region, and PZ in the parietal region. Amplitudes of N300 induced by picture-word matching were considerably different between the two experimental conditions at electrodes FZ and FCZ. Amplitudes of N400 were significantly larger in the incongruent condition than in the congruent condition.

CONCLUSION

The study demonstrated that N300 and N400 are promising indicators for measuring semantic congruence in future sign design.

APPLICATION

Our findings provide ERP indicators for measuring the semantic congruence of sign design, which can be easily applied to improve the efficiency of sign design and sign comprehension.

Comprehensibility of pharmaceutical pictograms: Effect of prospective-user factors and cognitive sign design features

BACKGROUND

The people's comprehensibility regarding the meaning of internationally recommended pictograms is an important factor in the correct usage of medications.

OBJECTIVE

To investigate the relationship between the guessability of the pharmaceutical pictograms, the cognitive sign features, and prospective-user factors.

METHODS

A total of 351 Iranian people participated in this study. Two questionnaires were used to measure guessability and cognitive design features regarding the pharmaceutical pictograms. A single-sheet questionnaire was also developed to collect demographic data.

RESULTS

According to the 67% correctness criterion suggested by ISO 3864:P3, 18 pictograms were understandable by the participants. Moreover, of the five cognitive features, "semantic closeness" and "meaningfulness" had the most correlation with the guessability score. In terms of personal factors, understanding of the pictograms' meaning was negatively correlated with age, while it had no association with the occupation.

CONCLUSIONS

Some pharmaceutical pictograms developed by reliable international organizations can be used in a community only after redesigning and testing among the prospective users. The findings indicated that some pharmaceutical pictograms were not comprehensible for most participants. It is therefore expected that using a combination of pictograms with written messages and training could help in conveying the messages by pharmaceutical pictograms.

Guessability of U.S. pharmaceutical pictograms in Iranian prospective users

Objective:

This study examined the gueassability of US pharmaceutical pictograms as well as associated demographic factors and cognitive design features among Iranian adults.

Methods:

A total of 400 participants requested to guess the meaning of 53 US pharmaceutical pictograms using the open-ended method. Moreover, the participants were asked to rate the cognitive design features of each pictorial in terms of familiarity, concreteness, simplicity, meaningfulness and semantic closeness on a scale of 0-100.

Results:

The average guessability score (standard deviation) was 66.30 (SD=24.59). Fifty-five percent of pharmaceutical pictograms understudy met the correctness criteria of 67% specified by ISO3864, while only 30% reached the criterion level of 85% set by ANSIz535.3. Low literate participants with only primary school education had substantial difficulty in the interpretation of pharmaceutical pictograms compared to those completed higher education levels. Younger adults of <30 years significantly performed better in the interpretation of pharmaceutical pictograms as compared to >31 years old participants. ‘Home patient care’ and ‘daily medication use’ had no effect on guessability performance. Concerning cognitive design features, meaningfulness better predict geussability score compared to the others.

Conclusions:

Several USP pictograms fail to be correctly interpreted by Iranian users and need to be redesigned respecting cognitive design features. Interface designers are recommended to incorporate more familiar and concrete elements into their graphics in order to create more meaningful pictorial symbols and to avoid any misinterpretation by the user. Much effective medication use is expected to be achieved by means of this approach, through the improvement of the communication property of pharmaceutical pictograms.

Evaluation of penalty and enforcement strategies to combat speeding offences among professional drivers: A Hong Kong stated preference experiment

Speeding has been a great concern around the world due to the occurrence and severity of road crashes. This paper presents an evaluation of the effectiveness of different penalty and camera-based enforcement strategies in curbing speeding offences by professional drivers in Hong Kong. A stated preference survey approach is employed to measure the association between penalty and enforcement strategies and drivers' speed choices. Data suggest that almost all drivers comply with speed limits when they reach a camera housing section of the road. For other road sections, a panel mixed logit model is estimated and applied to understand the effectiveness of penalties and enforcement strategies on driver's speeding behaviors. Driving-offence points (DOPs) are found to be more effective than monetary fines in deterring speeding offences, albeit there is significant heterogeneity in how drivers respond to these strategies. Warning drivers of an upcoming camera-based enforcement section increased speed compliance. Several demographic and employment characteristics, driving history and perception variables also influence drivers' choices of speed compliance. Finally, besides penalty and enforcement strategies, driver education and training programs aimed at addressing aggressiveness/risk-taking traits might help reduce repeated speeding offences among drivers.

Conveying Safety Messages on Agricultural Machinery: The Comprehension of Safety Pictorials in a Group of Migrant Farmworkers in Italy

The comprehension of safety signs affixed to agricultural machinery is fundamental to warning users about the residual risks which cannot be eliminated with machinery design and the adoption of protections. This is particularly relevant for the migrant workforce, which may encounter some language barriers with written safety communication. The present study aimed to investigate the comprehension of safety signs affixed to agricultural machinery in a group of migrants from both European and non-European countries employed in Italian agriculture. Thirty-seven migrant farmworkers (12 Indians, 17 Pakistanis, and eight Romanians) were individually interviewed to test the comprehension of four safety signs referring to the main causes of fatal and non-fatal injuries caused by interactions with farm machinery. Romanians obtained the highest comprehension performance (68.8% of correct answers), followed by Indians (35.4%), with Pakistanis being last (32.4%). The nationality and the previous experience as a farmworker significantly affected the comprehension of safety signs. The results pointed out the importance of adequately training migrants on the meaning of safety signs. Beside this, the study suggests a redesign of the signs, considering some signs' features to enhance pictorials' cross-cultural comprehension.

Comprehension of Safety Pictograms Affixed to Agricultural Machinery among Pakistani Migrant Farmworkers in Italy

Objectives: Safety pictograms are important graphic elements that are useful for rapidly conveying messages in workplaces. The purpose of this study was to investigate the comprehension of safety pictograms affixed to agricultural machinery among a group of Pakistani migrant farmworkers employed in Italy. Methods: Interviews about the meanings attributed to four standardized safety pictograms affixed to agricultural machinery depicting the most frequent causes of farm accidents were administered to 29 Pakistani migrant farmworkers employed on Italian farms. Results: There was high variability in pictogram comprehension. None of the participants interpreted all the pictograms in accordance with the definitions provided by the international standards. Higher comprehension rates were reported for pictograms related to the risks of tractor rollover and foot injury, while pictograms referring to the need to consult a technical manual and the risk of entanglement yielded lower comprehension scores. Previous farming experience in the country of origin and the number of years of education were significantly associated with comprehension scores. Conclusion: A discussion of pictogram features that may be critical for comprehension is provided, and (re)design suggestions are given to improve the cross-cultural comprehension of these safety signs.

Designing in-vehicle signs for connected vehicle features: Does appropriateness guarantee comprehension?

This paper discusses the design and evaluation of connected and cooperative vehicle in-vehicle sign designs displayed on a mobile phone: Emergency Electronic Brake Lights (EEBL), Emergency Vehicle Warning (EVW), Traffic Condition Warning, and Road Works Warning. Appropriateness and comprehension of each design alternative were assessed using quantitative (i.e. Likert scales) and qualitative (i.e. open-ended questions) methods. Forty-four participants took part in the study and were shown twelve dashboard camera videos presenting a total of eleven designs alternatives, displayed with or without a legend. Despite their appropriateness, EEBL and EVW signs displayed with a legend were better comprehended and less ambiguous than those displayed without a legend. Moreover, displaying a legend below the signs to warn drivers of an emergency braking ahead was efficient in low visibility condition and could potentially increase safety in critical situations.

Improving Safety and Efficiency of Roundabouts Through an Integrated System of Guide Signs

A roundabout can improve intersection capacity in some extent by reducing conflict points and traffic delays. However, the complex environment in a large roundabout does not provide essential directional information to motorists. Therefore, drivers must spend more time identifying the exit they want, which may influence the intersection capacity and safety. Using perceptual constancy, a new guide sign system for roundabouts was developed to improve sense of direction. In order to observe how the guide sign system would affect drivers’ sense of direction, a series of driving simulator experiments were conducted to evaluate driving performance. The test results revealed that the guide sign system can effectively improve the accuracy of exit identification and reduce travel time driving through a roundabout despite the gender and age differences among drivers. This paper proposes a continuous and gradual guide sign system for roundabouts that can be used to help improve drivers’ sense of direction, which is beneficial to improve the safety and efficiency of roundabout operations. These findings are indicative of the future development of traffic sign design and practice in a roundabout.

Expert evaluation of traffic signs: conventional vs. alternative designs

Traffic sign comprehension is significantly affected by their compliance with ergonomics design principles. Despite the UN Convention, designs vary among countries. The goal of this study was to establish theoretical and methodological bases for evaluating the design of conventional and alternative signs. Thirty-one conventional signs and 1-3 alternatives for each conventional sign were evaluated for their compliance with three ergonomics guidelines for sign design: physical and conceptual compatibility, familiarity and standardisation. Twenty-seven human factors and ergonomics experts from 10 countries evaluated the signs relative to their compliance with the guidelines. Analysis of variance across alternatives revealed that for 19 of the 31 signs, an alternative design received a significantly higher rating in its ergonomics design than the conventional sign with the same meaning. We also found a very high correlation between the experts' ratings and comprehension from previous studies. In conclusion, many countries use signs for which better alternative designs exist, and therefore UN Convention signs should be re-examined, and ergonomics experts evaluation can serve as a good surrogate for road users' comprehension surveys. Practitioner summary: This study presents theoretical and methodological bases for evaluating the design of UN Conventional and alternative traffic signs. Human factors and ergonomics experts evaluated 31 conventional and 68 alternative road signs, based on ergonomics principles for sign design. Results indicated the need to re-examine poorly designed UN Convention signs.

Traffic symbol recognition modulates bodily actions

Traffic signals, i.e., iconic symbols conveying traffic rules, generally represent spatial or movement meanings, e.g., “Stop”, “Go”, “Bend warning”, or “No entry”, and we visually perceive these symbols and produce appropriate bodily actions. The traffic signals are clearly thought to assist in producing bodily actions such as going forward or stopping, and the combination of symbolic recognition through visual perception and production of bodily actions could be one example of embodied cognition. However, to what extent our bodily actions are associated with the symbolic representations of commonly used traffic signals remains unknown. Here we experimentally investigated how traffic symbol recognition cognitively affects bodily action patterns, by employing a simple stimulus-response task for traffic sign recognition with a response of either sliding or pushing down on a joystick in a gamepad. We found that when operating the joystick, participants’ slide reaction in response to the “Go” traffic symbol was significantly faster than their push reaction, while their response time to the “Stop” signal showed no differences between sliding and pushing actions. These results suggested that there was a possible association between certain action patterns and traffic symbol recognition, and in particular the “Go” symbol was congruent with a sliding action as a bodily response. Our findings may thus reveal an example of embodied cognition in visual perception of traffic signals.

Investigation of the Contributory Factors to the Guessability of Traffic Signs

Traffic signs play an important role in traffic management systems. A variety of studies have focused on drivers’ comprehension of traffic signs. However, the travel safety of prospective users, which has been rarely mentioned in previous studies, has attracted considerable attention from relevant departments in China. With the growth of international and interregional travel demand, traffic signs should be designed more universally to reduce the potential risks to drivers. To identify key factors that improve prospective users’ sign comprehension, this study investigated eight factors that may affect users’ performance regarding sign guessing. Two hundred and one Chinese students, all of whom intended to be drivers and none of whom had experience with daily driving after obtaining a license or visits to Germany, guessed the meanings and rated the sign features of 54 signs. We investigated the effects of selected user factors on their sign guessing performance. Additionally, the contributions of four cognitive design features to the guessability of traffic signs were examined. Based on an analysis of the relationships between the cognitive features and the guessability score of signs, the contributions of four sign features to the guessability of traffic signs were examined. Moreover, by exploring Chinese users’ differences in guessing performance between Chinese signs and German signs, cultural issues in sign design were identified. The results showed that vehicle ownership and attention to traffic signs exerted a significant influence on guessing performance. As expected, driver’s license training and the number of years in college were dominant factors for guessing performance. With regard to design features, semantic distance and confidence in guessing were two dominant factors for the guessability of signs. We suggest improving the design of signs by including vivid, universal symbols. Thus, we provide several suggestions for designing more user-friendly signs.

Investigating the role of socio-economic factors in comprehension of traffic signs using decision tree algorithm

INTRODUCTION

Drivers' ability to comprehend the meaning of traffic signs is essential to safe driving. Drivers' personal characteristics are believed to play a crucial role in determining drivers' comprehension of traffic signs.

METHOD

This study investigates the role of age, gender, marital status, license category, educational level, driving experience, monthly income, and number of traffic violation during the last five years in drivers' comprehension of 39 posted traffic signs in the city of Irbid, Jordan. These signs include 15 regulatory signs, 17 warning signs, and 7 guidance signs. A total of 400 paper-based surveys were completed by drivers with different socio-economic characteristics. Subsequently, a decision tree was created for each category of traffic signs to identify the most influential factors affecting drivers' comprehension. Each tree was created twice; once using the whole data set for building and validating the tree, and a second time only using 80% of the data for building and 20% for validating.

RESULTS

The accuracy of the generated trees in predicting drivers' comprehension of regulatory, guidance, and warning traffic signs was 70%, 71%, and 66.5%, respectively, when using the whole data for building and validating the tree, and was 65%, 62.5%, and 61.3%, respectively, when using only 80% of the data for building and the remaining for validating.

CONCLUSIONS

The generated decision trees showed that driving experience, marital status, age, and education background are the most influential factors in determining drivers' comprehension of traffic signs as they were primary splitters in such trees.

PRACTICAL APPLICATION

The rules obtained from the decision tree can be utilized by transportation agencies to determine the drivers who need help with understanding the road traffic signs.

How to warn drivers in various safety-critical situations - Different strategies, different reactions

Technological advances allow supporting drivers in a multitude of occasions, ranging from comfort enhancement to collision avoidance, for example through driver warnings, which are especially crucial for traffic safety. This psychological driving simulator experiment investigated how to warn drivers visually in order to prevent accidents in various safety-critical situations. Collision frequencies, driving behavior and subjective evaluations of situation criticality, warning understandability and helpfulness of sixty drivers were measured in two trials of eight scenarios each (within-subjects factors). The warning type in the head-up display (HUD) varied (between-subjects) in its strategy (attention-/reaction-oriented) and specificity (generic/specific) over four warning groups and a control group without a warning. The results show that the scenarios differed in their situation criticality and drivers adapted their reactions accordingly, which underlines the importance of testing driver assistance systems in diverse scenarios. Besides some learning effects over the trials, all warned drivers showed faster and stronger brake reactions. Some warning concepts were understood better than others, but all were accepted. Generic warnings were effective, yet the warning strategy should adapt to situation requirements and/or driver behavior. A stop symbol as reaction generic warning is recommendable for diverse kinds of use cases, leading to fast and strong reactions. However, for rather moderate driver reactions an attention generic approach with a caution symbol might be more suitable. Further research should investigate multi-stage warnings with adaptive strategies for application to various situations including other modalities and false alarms.

Research on Visual Cognition About Sharp Turn Sign Based on Driver’s Eye Movement Characteristic

As a traffic language, sharp turn sign is a kind of important road infrastructure that indicates a sharp turning will show up at the coming road, warning drivers to slow down to ensure the driving safety. In this paper, real vehicle test was carried out on mountain road with an eye tracker equipment. At different driving speeds, parameters of eye movement characteristics in the visual cognition process of sharp turn signs were collected, including distribution of gaze points, fixation and saccade. Simultaneously, driver’s scan paths of recognizing sharp turn signs with different supporting forms were gathered. The results of the analysis of testing data showed that the dispersion of distribution of gaze points would increase with driving velocity. Saccade was the main method for driver to capture information of sharp turn signs. While driving speed was lower than 60[Formula: see text]km/h, fixation was also one of the methods. For the visual cognition process of sharp turn sign with cantilever, compared to post, the searching scope was wider both in horizontal and vertical directions. This study is beneficial to evaluate the rationality of sharp turn signs, promoting the using efficiency of signs and improving the driving safety on mountain road.

Safety signs on agricultural machinery: Pictorials do not always successfully convey their messages to target users

This study investigated the extent to which a sample of Italian users comprehended safety pictorials used on agricultural machinery. A questionnaire with 12 safety pictorials was administered to 248 users of agricultural machinery. For each of the pictorials, the participants were asked to select the most appropriate description of four written choices. The investigated safety pictorials were, in general, not well comprehended. Two different classes of participants were identified, each with a different level of comprehension. The participants with better comprehension were characterized by the regular use of agricultural machinery and frequent previous exposure to pictorials. The need for training courses focusing on safety pictorials and their meanings, as well as the need for improvement to the pictorials themselves to make them more easily comprehended, is discussed.

Design and cognitive evaluation of 6 dynamic lane departure warning symbols

OBJECTIVE

Lane departure, caused by inattention, distraction, drowsiness, or any unusual driver behavior, is a typical risk threatening the driver as well as other road users. Accurate perception of such situations through effective warnings would help drivers to avoid serious consequences. With regard to critical functions of warning symbols for risk communication, the present study focused on providing effective and easily perceivable symbols, compatible with human cognitive capabilities. Thus, the main purpose of the present study was to design and cognitively appraise 6 newly designed dynamic symbols, candidates for a new type of lane departure warning system.

METHODS

Simplicity, familiarity, concreteness, meaningfulness, and semantic closeness were the major assessment criteria, defining cognitive features by the earlier researchers in the field. A total number of 187 driving license applicants, with a mean age of 20.58 years (SD = 3.20), participated in the present survey. The participants rated cognitive features of the 6 dynamic symbols along a 0-100 scale.

RESULTS

Significant main effect of the element factor type of the designed symbols on rating cognitive features revealed that the existence of car element was the best predictor for illustrating lane departure. The interaction of both element factor and location of element factor significantly affected the ratings. However, the location of element factor did not solely have any strong effect on the ratings. The results also demonstrated that semantic closeness received the highest overall mean score across symbols (M = 61.80), especially within the symbols that include the car element (M = 75.67). Moreover, a significant difference was observed between the average ratings of the cognitive features, despite the fact that a significant correlation was found between cognitive features.

CONCLUSION

The most considerable result of the current study was the match between the symbol with the highest ratings and the International Organization for Standardization (ISO)-related icon in appearance. Because previous studies demonstrated a strong correlation between comprehension scores of the symbol and both semantic closeness and meaningfulness, high-level comprehensibility of the best ranked symbol is expected.

Design Factors Affecting the Reaction Time for Identifying Toilet Signs: A Preliminary Study

This study focused on the manner in which design factors affect the reaction time for identifying toilet signs. Taiwanese university students and staff members (50 men, 50 women; M age = 23.5 year, SD = 5.7) participated in the study. The 36 toilet signs were modified on three factors (six presenting styles, two figure-ground exchanges, and three colors), and the reaction time data of all participants were collected when the signs were presented in a simulation onscreen. Participants were quickest when reading Chinese text, followed by graphics and English texts. The findings also showed that men and women had different reaction times across various design combinations. These findings can serve as a reference for practically designing toilet signs, since design factors can lead to difficulties with comprehension based on reaction time measurements.

Differential effects of traffic sign stimuli upon speeding in school zones following a traffic light interruption

Motorists whose journey has been interrupted by signalized traffic intersections in school zones resume their journey at a faster vehicle speed than motorists who have not been required to stop. Introducing a flashing "check speed" sign 70m after the traffic intersections counteracts this interruptive effect. The present study examined which aspects of a reminder sign are responsible for reducing the speeding behavior of interrupted motorists. When a sign that combines both written text and flashing lights was introduced, interrupted motorists did not speed, traveling on average 0.82km/h below the 40km/h speed limit when measured 100m from traffic intersections. Alternatively, when only the flashing lights were visible the interrupted motorists sped 3.36km/h over the 40km/h speed limit. Similar vehicular speeds were observed when only the written text was visible and when no sign was present (7.67 and 7.49km/h over the 40km/h speed limit, respectively). This indicates that static reminder signs add little value over the absence of a school zone reminder sign; the presence of both cues is necessary to fully offset the interruptive effect. This study also highlights the benefit of using exogenous visual cues in traffic signs to capture drivers' attention. These findings have practical implications for the design and use of traffic signs to increase compliance with posted speed limits.

Comprehension of safety pictograms affixed to agricultural machinery: A survey of users

INTRODUCTION

Pictograms affixed to agricultural machinery are important tools to reduce the occurrence of accidents and injuries when correctly noticed, comprehended, and followed. This study investigated the knowledge of safety pictograms used in agricultural machinery in a sample of farmers and farm workers and examined the factors influencing their comprehension.

METHOD

A questionnaire with 12 safety pictograms used for agricultural machinery was administered to 281 owners or users of agricultural machinery. For each of the pictograms, the participants had to select the most appropriate verbal description from among four choices.

RESULTS

The pictograms examined yielded poor comprehension scores, including warnings related to the most frequent accidents involving agricultural machinery. Familiarity with the pictograms and years of experience with agricultural machinery significantly increased users' comprehension of the meaning of the pictograms.

CONCLUSIONS

Specific training programs should be designed to draw attention to safety pictograms and to instill their meaning.

Effects of fog, driver experience and gender on driving behavior on S-curved road segments

Driving on curved roads has been recognized as a significant safety issue for many years. However, driver behavior and the interactions among variables that affect driver performance on curves is complicated and not well understood. Previous studies have investigated various factors that influence driver performance on right- or left-turn curves, but have paid little attention to the effects of foggy weather, driver experience and gender on driver performance on complex curves. A driving simulator experiment was conducted in this study to evaluate the relationships between driving behavior on a continuous S-curve and foggy weather, driver experience and gender. The process of negotiating a curve was divided into three stages consisting of a straight segment, the transition from the straight segment to the S-curve and the S-curve. The experimental results indicated that drivers tended to drive more cautiously in heavy fog, but the driving risk was still increased, especially in the transition stage from the straight segment to the S-curve. The non-professional (NP) drivers were less sensitive to the impending change in the road geometry, and less skilled in both longitudinal and lateral vehicle control than the professional drivers. The NP female drivers in particular were found to be the most vulnerable group in S-curve driving.

Matching performance of vehicle icons in graphical and textual formats

The current research classified 82 vehicle icons into seven categories (image-related, concept-related, semi-abstract, arbitrary, abbreviation, word, and combined) for their matching accuracy, matching sequence, and matching time. These data can be compared and used as a framework for future icon development. Forty participants, all with a university degree, took part in this experiment. Half of the participants had intensive driving experience, while the other half never driven a car. The results indicated that on average, word icons had a significantly greater matching accuracy than the other icon formats; ranging from 4.7 to 20.8% difference. Regarding the matching sequence, participants matched image-related icons before other icon formats. Arbitrary and combined icons took significantly longer to match than other icon formats by 1.4-6.2 s. Based on the high matching accuracy (86.3%) and high ratings on subjective design features, word format can be used for functions describable using simple English for users with English reading ability. Confusion matrices showed that 63.2% of the misunderstandings were caused by similarity in format or function.

The effects of sign design features on bicycle pictorial symbols for bicycling facility signs

The inanimate bicycle symbol has long been used to indicate the animate activity of bicycling facility signs. In contrast, either the inanimate bicycle symbol or the animate bicycle symbol has been used interchangeably for the standard pavement symbols in bike lanes. This has led to confusion among pedestrians and cyclists alike. The purpose of this study was to examine two different designs (inanimate symbol vs. animate symbol) involved in the evaluation of perceived preference and glance legibility, and investigate sign design features on bicycle pictorial symbols. Thirty-five participants compared current bicycle signs (inanimate symbols) to alternative designs (animate symbols) in a controlled laboratory setting. The results indicated that the alternative designs (animate symbols) showed better performance in both preference and glance legibility tests. Conceptual compatibility, familiarity, and perceptual affordances were found to be important factors as well.

The effects of age on symbol comprehension in central rail hubs in Taiwan

The purpose of this study was to investigate the effects of age and symbol design features on passengers' comprehension of symbols and the performance of these symbols with regard to route guidance. In the first experiment, 30 young participants and 30 elderly participants interpreted the meanings and rated the features of 39 symbols. Researchers collected data on each subject's comprehension time, comprehension score, and feature ratings for each symbol. In the second experiment, this study used a series of photos to simulate scenarios in which passengers follow symbols to arrive at their destinations. The length of time each participant required to follow his/her route and his/her errors were recorded. Older adults experienced greater difficulty in understanding particular symbols as compared to younger adults. Familiarity was the feature most highly correlated with comprehension of symbols and accuracy of semantic depiction was the best predictor of behavior in following routes.

Comprehensibility of traffic signs among urban drivers in Turkey

Traffic signs are commonly used traffic safety tools, mainly developed to provide crucial information in a short time to support safe drive; but the success depends on their comprehensibility by the drivers. Also, a sudden change in the traditionally used and accepted signs can cause significant safety problem, as in the case of cancellation of red oblique bars in 2004 as a part of the European Union Harmonization Process of Turkey. Having a severe traffic safety problem in Turkey, a need to assess both the comprehensibility of internationally accepted traffic signs and current level of driver education, was the main motivation behind this study. A paper-based survey study in 2009 that reached a sample of 1478 urban drivers in the City of Ankara, focused on the determination of comprehensibility of 30 selected traffic signs, which are commonly used and critical for safety, including two recently changed signs. The meaning of each sign is sought using an open-ended question format to capture different levels and types of comprehensions, which enabled the detection of "opposite" and "partially correct" answers besides "wrong" and "correct" ones. High comprehensibility of 9 control group signs shows the validity of the study. The recently changed signs are among the oppositely associated ones proving the increased risk in traffic safety and need for more aggressive campaigning to publicize them.

Investigation of the effectiveness of traffic sign training in terms of training methods and sign characteristics

OBJECTIVE

This research investigated whether different training methods had any effect on the effectiveness of traffic sign training and whether there were any relationships between traffic sign characteristics and effectiveness of the training.

METHODS

Thirty-six participants were randomly assigned into 4 equal-sized groups (control, paired-associate learning, recall training, and recognition training) to study the learnability of Mainland China traffic signs. In paired-associate learning, participants studied each traffic sign along with a referent describing its meaning. In addition to being informed of the meaning of traffic signs, both recall training and recognition training provided participants with questions and feedback. For recall training, the questioning process was a recall task in which participants had to produce a meaning for a given traffic sign from memory. For recognition training, the questioning process was a recognition task that required participants to identify the most appropriate referent corresponding to a given sign. No traffic sign training was given to the control group.

RESULTS

Each training method significantly improved comprehension of the meaning of traffic signs. Participants from recall training performed better in a posttraining test than those from paired-associate learning and recognition training, indicating that the recall training elicited a deeper level of learning. In addition, questioning and feedback had a positive influence on training effectiveness. Performance in the posttest was found to be better when the questioning process matched the test process. Regarding the traffic sign characteristics, semantic closeness had a long-lasting effect, in terms of the timescale of this experiment on traffic sign comprehension, and traffic signs were perceived as more meaningful after their intended meanings were studied.

CONCLUSIONS

Recall training is more effective in enhancing comprehension of traffic signs than paired-associate learning and recognition training. The findings of this study provide a basis for useful recommendations for designing symbol-training programs to improve road safety for road users.