The effects of pedestrian gestures on driver yielding at crosswalks: A systematic replication

Applied research on decreasing pedestrian injuries often focuses on how to increase driver yielding behavior but rarely studies what pedestrians can do to increase their safety. There is a lack of empirical research focusing on how pedestrians can effectively signal their need to cross the street when there is no traffic light directing the pedestrian and oncoming traffic. As a replication and extension of Crowley-Koch et al. (2011), this study examined the effects of two pedestrian gestures, an extended arm and raised hand, on driver yielding behavior at 3 crosswalks in Oklahoma City. Research assistants implemented gestures prior to crossing the street as cars approached the crosswalk. Data were collected on the percentage of drivers yielding to the pedestrian. Both pedestrian gestures increased driver yielding across all 3 sites when compared to no gesture. Results were discussed in terms of future research and practical solutions towards increasing pedestrian safety.

Examining generalization of motorist yielding at an adjacent crosswalk with variations of the gateway sign configuration

The gateway sign configuration has been effective at increasing motorist yielding and reducing speeds at crosswalks. A gateway configuration uses in-street signs at a crosswalk on each edge of the roadway and on each lane line. Although this intervention is effective at increasing motorist yielding at uncontrolled crosswalks, the limits of the intervention have yet to be tested. The present study examined if 1) the effects of the gateway intervention on one crosswalk would generalize to an untreated adjacent crosswalk, and 2) if the effects of an offset configuration of signs which partially treated each crosswalk could maximize the effects of that generalization. Experiment 1 showed that less yielding occurred at the untreated crosswalk than at the treated crosswalk, though yielding was higher than baseline. In Experiment 2, results showed that an offset gateway configuration could produce comparable levels of yielding at both crosswalks.

How does an increased freeway speed limit influence the frequency of crashes on adjacent roads?

Urban arterial roads carry the most traffic on urban road networks and experience the highest percentage of crashes in urban areas. Safety on urban arterials that are adjacent to a higher speed freeway may be impacted by speed spillover or adaptation. The objective of this study was to determine the effects of raising freeway speed limits on the frequency of crashes on urban arterial roads adjacent to freeways (spillover effects). Crash data within Michigan were collected on 1393 urban arterial road segments before and after freeway speed limits were altered. Before-and-after data was collected simultaneously on 1470 comparison segments of urban arterial where speed limits did not change to control for the regression-to-the-mean bias. The mixed effects negative binomial (MENB) regression model was developed to analyze crash frequency on urban arterials. The results indicate that raising speed limits of freeways by as little as five miles per hour had a likelihood of increasing crash frequency on adjacent arterial roads by as much as 13.9 percent. To investigate if the safety impact of speed spillover changes with the distance from the freeway, influence areas (0-1 mile, 1-2 mile, and 2-3 mile) were used. The findings of this study provide insights into the effects of speed spillover on crash occurrences, and it demonstrates that increasing freeway speed limit has a negative influence on driver compliance with the speed limit on adjacent arterial roads. Correspondingly, the influence of freeway speed on drivers' speeding behavior on adjacent urban arterials fades away with the distance from the freeway.

Public Posting in the Classroom: Comparison of Posting Names and Coded Numbers of Individual Students

In the present study, the effects of publicly posting names were compared with coded numbers in a classroom. Four third-grade classes of 63 boys and 54 girls whose mean age was 8.5 yr. participated. The weekly spelling test results monitored over 4 mo. show similar improvements under both public posting procedures. A similar pattern of results was found for students identified as having difficulty in spelling. The results are discussed in terms of ethical considerations when using public posting.

Time-series intervention analysis of pedestrian countdown timer effects

Pedestrians account for 40-50% of traffic fatalities in large cities. Several previous studies based on relatively small samples have concluded that Pedestrian Countdown Timers (PCT) may reduce pedestrian crashes at signalized intersections, but other studies report no reduction. The purposes of the present article are to (1) describe a new methodology to evaluate the effectiveness of introducing PCT signals and (2) to present results of applying this methodology to pedestrian crash data collected in a large study carried out in Detroit, Michigan. The study design incorporated within-unit as well as between-unit components. The main focus was on dynamic effects that occurred within the PCT unit of 362 treated sites during the 120 months of the study. An interrupted time-series analysis was developed to evaluate whether change in crash frequency depended upon of the degree to which the countdown timers penetrated the treatment unit. The between-unit component involved comparisons between the treatment unit and a control unit. The overall conclusion is that the introduction of PCT signals in Detroit reduced pedestrian crashes to approximately one-third of the preintervention level. The evidence for this reductionis strong and the change over time was shown to be a function of the extent to which the timers were introduced during the intervention period. There was no general drop-off in crash frequency throughout the baseline interval of over five years; only when the PCT signals were introduced in large numbers was consistent and convincing crash reduction observed. Correspondingly, there was little evidence of change in the control unit.

The effects of external motivation and real-time automated feedback on speeding behavior in a naturalistic setting

OBJECTIVE

In this field experiment, the authors tested an alerting system and a monetary incentive system with the objective of reducing speeding more than 5 mph faster than the posted speed limit.

BACKGROUND

Speeding is a factor in a significant number of traffic fatalities. The systems tested in this project have been evaluated outside but not within the United States. These studies indicated that similar systems led to reductions in speeding.

METHOD

For this study, eight vehicles were instrumented such that vehicle speed and speed limits were linked in real time. A total of 50 participants drove assigned vehicles for 4 weeks. Week 1 was a baseline period; during Week 2 or Week 3, 40 participants experienced the alerting system that issued auditory and visual advisory signals when drivers exceeded the limit by 5 mph or more. Of these 40 individuals, 20 experienced the monetary incentive system during Weeks 2 and 3; Week 4 was a return-to-baseline period. A control group of 10 drivers experienced neither system during the study.

RESULTS

Results indicated that the incentive system resulted in significant reductions in driving faster than the posted limit, and the feedback system led to modest changes in speeding. In the condition in which drivers experienced the feedback and incentive, reductions in speeding were similar to those found during the incentive-only condition.

CONCLUSION

The technology tested in this study has potential to benefit traffic safety by reducing the incidence of driving faster than the posted limit, which should lead to a reduction in speed-related crashes.

APPLICATION

Insurers provide incentive-based discounts on premiums. Combining this technology with such a discount program may improve traffic safety significantly.

The effects of a rectangular rapid-flashing beacon on vehicle speed

In 2008, nearly 31% of vehicle fatalities were related to failure to adhere to safe vehicle speeds (National Highway Traffic Safety Administration [NHTSA], 2009). The current study evaluated the effect of a rectangular rapid-flashing beacon (RRFB) triggered by excessive speed on vehicle speed using a combined alternating treatments and reversal design. The percentage of vehicles traveling above 41 mph (66 km per hour) decreased by 20%, and speed distributions showed a shift toward lower speeds during the RRFB condition.

Increasing following headway with prompts, goal setting, and feedback in a driving simulator

We evaluated the effects of prompting, goal setting, and feedback on following headway of young drivers in a simulated driving environment and assessed whether changes produced in following headway were associated with reductions in hard braking when drivers were and were not using cell phones. Participants were 4 university students. During baseline, drivers spent half of the time talking on cell phones while driving. At the start of the intervention, drivers were prompted to increase following headway while on the cell phones and were provided a specific target for following headway. Drivers were given feedback on increasing following headway when on cell phones at the end of each session. The intervention package was associated with an increase in following headway and a decrease in hard braking when participants were on and off the cell phones. Cell phone use did not affect any of the measures.

A feedback intervention to increase digital and paper checklist performance in technically advanced aircraft simulation

This study examined whether pilots operating a flight simulator completed digital or paper flight checklists more accurately after receiving postflight graphic and verbal feedback. The dependent variable was the number of checklist items completed correctly per flight. Following treatment, checklist completion with paper and digital checklists increased from 38% and 39%, respectively, to nearly 100% and remained close to 100% after feedback and praise for improvement were withdrawn. Performance was maintained at or near 100% during follow-up probes.

Using accelerator pedal force to increase seat belt use of service vehicle drivers

This study evaluated a device that applied a sustained increase in accelerator pedal back force whenever drivers exceeded a preset speed criterion without buckling their seat belts. This force was removed once the belt was fastened. Participants were 6 commercial drivers who operated carpet-cleaning vans. During baseline, no contingency was in place for unbuckled trips. The pedal resistance was introduced via a multiple baseline design across groups. On the first day of treatment, the device was explained and demonstrated for all drivers of the vehicle. The treatment was associated with an immediate sustained increase in seat belt compliance to 100%. Occasionally, drivers initially did not buckle during a trip and encountered the force. In all instances, they buckled within less than 25 s. These results suggest that the increased force was sufficient to set up an establishing operation to reinforce seat belt buckling negatively. Drivers indicated that they were impressed with the device and would not drive very long unbelted with the pedal force in place.

Effects of pedestrian prompts on motorist yielding at crosswalks

Pedestrian safety is a serious concern at busy intersections and pedestrian campuses across the nation. Although crosswalks and signs inform pedestrians where to cross, there is no standard protocol for pedestrians to signal drivers that they wish to use the crosswalks, except to stand in or at the crosswalk. We examined the effects of two pedestrian prompts, a raised hand and extended arm, on motorist yielding at uncontrolled crosswalks. The two prompts were effective at increasing yielding.

Increasing seat belt use in service vehicle drivers with a gearshift delay

This study evaluated a device that prevents drivers from shifting vehicles into gear for up to 8 s unless seat belts are buckled. Participants were 101 commercial drivers who operated vans, pickups, or other light trucks from the U.S. and Canada. The driver could escape or avoid the delay by fastening his or her seat belt before shifting out of park. Unbelted participants experienced either a constant delay (8 s) or a variable delay (M  =  8 s). A 16-s delay was introduced for those U.S. drivers who did not show significant improvement. Seat belt use increased from 48% to 67% (a 40% increase) for U.S. drivers and from 54% to 74% (a 37% increase) for Canadian drivers. The fixed delay was more effective for U.S. drivers than the variable delay, but there was no difference between these two delay schedules for Canadian drivers. After the driver fastened his or her seat belt, it tended to remain fastened for the duration of the trip.

The effects of advance stop lines and sign prompts on pedestrian safety in a crosswalk on a multilane highway

The effects of specific signs and stop line bars designed to influence motorists to stop further back from the crosswalk when yielding right of way to pedestrians were evaluated using a reversal design. The introduction of the prompt and stop line reduced motor vehicle-pedestrian conflicts (near collisions) by almost 80%. This finding was replicated in a second experiment the following year on two streets using a multiple baseline design. The use of the advance stop line is now being incorporated by the Provincial Department of Transportation for marking crosswalks on multilane streets.

Feedback interventions and driving speed: A parametric and comparative analysis

Five experiments were conducted to assess the effects of several variables on the efficacy of feedback in reducing driving speed. Experiment 1 systematically varied the criterion used to define speeding, and results showed that the use of a lenient criterion (20 km/hr over the speed limit), which allowed for the posting of high percentages of drivers not speeding, was more effective in reducing speeding than the use of a stringent criterion (10 km/hr over the speed limit). In Experiment 2 an analysis revealed that posting feedback reduced speeding on a limited access highway and the effects persisted to some degree up to 6 km. Experiments 3 and 4 compared the effectiveness of an unmanned parked police vehicle (Experiment 3) and a police air patrol speeding program (Experiment 4) with the feedback sign and determined whether the presence of either of these enforcement variables could potentiate the efficacy of the sign. The results of both experiments demonstrated that although the two enforcement programs initially produced larger effects than the feedback sign, the magnitude of their effect attenuated over time. Experiment 5 compared the effectiveness of a traditional enforcement program with a warning program which included handing out a flier providing feedback on the number and types of accidents occuring on the road during the past year. This experiment demonstrated that the warning program produced a marked reduction in speeding and the traditional enforcement program did not. Furthermore, the warning program and a feedback sign together produced an even greater reduction in speeding than either alone.

An analysis of several variables influencing the efficacy of flash card instruction

We conducted four experiments using an alternating treatments design to assess the influence of several variables on children's acquisition of number facts during one-on-one flash card instruction. In Experiment 1, we manipulated the order of stimulus presentation; in most cases a higher percentage of correct responses occurred, and mastery criterion was reached in somewhat fewer sessions, when a missed problem was re-presented after the next item than when problems were re-presented in a sequential order. In Experiment 2 a comparison of error-contingent reprimands with no reprimands yielded similar results in favor of the former procedure. Experiment 3 indicated that a higher percentage of correct responses and more rapid acquisition occurred when the tutor and student were seated knee-to-knee than when a desk was positioned between them. Experiment 4 compared the rate of learning in the presence and absence of a treatment package consisting of all three variables identified as leading to more rapid learning in the previous three experiments. Children reached criterion in less than half the time when the treatment package was in effect.

An analysis of public posting in reducing speeding behavior on an urban highway

The effects of public posting on speeding behavior on an urban highway were assessed using a reversal design. During baseline the percentage of drivers speeding was measured with a concealed radar unit. During the daily posting condition a highway sign was installed which provided feedback on the percentage of drivers not speeding yesterday and the best record to date. This sign was then covered and reintroduced. Results indicated that the sign was effective in reducing speeding behavior. Furthermore, the effects were most pronounced in reducing the speeds of the faster drivers. Next, daily and weekly postings were compared with the sign alone without numerical feedback: results revealed that the weekly posting condition was as effective as the daily posting condition, but that the sign had no influence when numbers were not posted. Finally, the weekly posting procedure remained effective during a 6-month follow-up condition.

Increasing driver yielding and pedestrian signaling with prompting, feedback, and enforcement

The effects of an intervention package on drivers' yielding to pedestrians and on pedestrians' signaling their intention to cross the street were assessed using a multiple baseline design. The intervention, which consisted of publicly posted feedback on the percentage of motorists yielding to pedestrians, small signs prompting pedestrians to engage in appropriate crossing behavior, and an enforcement program involving the use of warning tickets and feedback fliers, was sequentially introduced on two streets. The intervention more than doubled the percentage of motorists yielding to pedestrians and increased the percentage of pedestrians signaling their intention to cross the street to over 13% from a baseline level of less than 1%. Near misses involving pedestrians decreased by more than 50% on the narrower of the two streets.

Reducing elevator energy use: A comparison of posted feedback and reduced elevator convenience

The effects of two different procedures for reducing elevator energy use were assessed using a multiple-baseline design. In the first procedure, feedback about the amount of energy consumed by the elevators each week was posted on each elevator door. Later, signs advocating the use of stairs to save energy and improve health were posted next to the feedback signs. In the second procedure, the time required to travel between floors was increased by adding a delay to the elevator door closing mechanisms. Results indicated that neither feedback alone nor feedback plus educational signs reduced the amount of energy consumed by the elevators. However, use of the door delay reduced consumption by one-third in all elevators.A second experiment replicated the effect of the door delay on energy consumption and, in addition, demonstrated that the door delay also produced a reduction in the number of persons using the elevator. The second experiment also showed that, following an initial period during which a full delay was in effect, a gradual reduction of the delay interval resulted in continued energy conservation. Reduced convenience as a general strategy for energy conservation is discussed.

A comparison of the effects of posted feedback and increased police surveillance on highway speeding

A counterbalanced, reversal design was used to compare the effectiveness of posted feedback and increased police surveillance in reducing speeding on two urban highways. Drivers' speeds were measured using a concealed radar unit. During public posting, a large highway sign, which listed the percentage of drivers not speeding during the preceding week and the best record to date, was erected on each street. Use of the feedback sign alternated with periods of baseline and periods of increased police surveillance and ticketing. During increased police surveillance, highly visible, stationary police radar patrols were established along the highways for either 30 min or 60 min per day, 5 days per week. Results indicated that although public posting was highly effective in reducing the percentage of speeding drivers, increased police surveillance was not. Thus, since the feedback sign required only 30 min per week to maintain, public posting was at least 10 times more efficient in controlling speeding than was police surveillance and ticketing.

The effect of feedback on the accuracy of checklist completion during instrument flight training

This study examined whether pilots completed airplane checklists more accurately when they receive postflight graphic and verbal feedback. Participants were 8 college students who are pilots with an instrument rating. The task consisted of flying a designated flight pattern using a personal computer aviation training device (PCATD). The dependent variables were the number of checklist items completed correctly. A multiple baseline design across pairs of participants with withdrawal of treatment was employed in this study. During baseline, participants were given postflight technical feedback. During intervention, participants were given postflight graphic feedback on checklist use and praise for improvements along with technical feedback. The intervention produced near perfect checklist performance, which was maintained following a return to the baseline conditions.

Observations of how drivers fasten their seatbelts in relation to various startup tasks

Observational data were collected to determine the percentage of drivers that followed various seatbelt buckling sequences. Observers scored the buckling sequence and recorded the time between various startup events and fastening the seatbelt of 1600 drivers in two urban areas, Pinellas County, Florida, and Halifax, Nova Scotia, Canada. The results indicated that most drivers waited to buckle their seatbelt until after they started their vehicle or placed it into gear, with a substantial proportion buckling after placing the vehicle in motion. These results suggest that a salient second seatbelt reminder that was initiated 30s after placing the vehicle in gear would only be experienced by persons who do not buckle their seatbelt and less than 1% of drivers who buckle their seatbelt more than 29 s after placing the vehicle in gear.

Recognition distance of pedestrian traffic signals by individuals with low vision

Forty-one individuals with moderate-to-severe vision loss participated in a study to determine the minimum distance they required to correctly identify three different pedestrian traffic icon symbols, one of which was presented with an augmented light source. We found that subjects could identify the WALK icon without the augmented light source information, or animated eyes, from farther away than either the WALK icon with the augmented light source information or the DON'T WALK icon. These results differ from those of a previous study, which found that subjects could correctly identify the WALK icon with the augmented light source from a greater distance than the WALK or DON'T WALK icons without the augmented light source.

Impact of a comprehensive safety program on bicycle helmet use among middle-school children

A bicycle helmet program was evaluated in three middle schools using a multiple baseline across schools design. Two of the three schools had histories of enforcement of helmet use. During baseline many students riding their bikes to and from school did not wear their helmets or wore them incorrectly. A program that consisted of peer data collection of correct helmet use, education on how to wear a bicycle helmet correctly, peer goal setting, public posting of the percentage of correct helmet use, and shared reinforcers, all of which were implemented by the school resource officer, increased afternoon helmet use and afternoon correct helmet use in all three schools. Probe data collected a distance from all three schools indicated that students did not remove their helmets once they were no longer in close proximity to the school, and probe data collected in the morning at two of the schools showed that the behavior change transferred to the morning.

Evaluation of two methods of prompting drivers to use specific exits on conflicts between vehicles at the critical exit

The Florida Department of Transportation used a series of changeable-message signs that functioned as freeway guide signs to divert traffic to Universal Theme Park via one of two eastbound exits based on traffic congestion at the first of the two exits. An examination of crashes along the entire route indicated a statistically significant increase in crashes at the first eastbound exit following the actuation of the system. Furthermore, all of the crashes occurred in close proximity to the exit gore (the crosshatched area at exits that drivers are not supposed to enter or traverse) at the first exit. In Experiment 1, behavioral data were collected using an alternating treatments design. These data revealed that reassigning the exit signs was effective in producing a change in the percentage of drivers using each of the two exits. These data also showed that the reassignment of the theme park exit was associated with an increase in the percentage of motor vehicle conflicts that consisted of vehicles cutting across the exit gore. An analysis revealed that the method used for switching the designated or active theme park exit on the series of changeable-message signs led to the presentation of conflicting messages to some motorists, thus resulting in erratic driving behavior (cutting across the exit gore). In Experiment 2, the treatment evaluated the use of a phased method of switching the designated theme park exit to eliminate the delivery of conflicting messages. The new method for switching the designated theme park exit was not associated with an increase in motorists cutting across the exit gore.

The effects of a seatbelt-gearshift delay prompt on the seatbelt use of motorists who do not regularly wear seatbelts

A seatbelt-gearshift delay was evaluated in two U.S. and three Canadian vehicles using a reversal design. The seatbelt-gearshift delay required unbelted drivers either to buckle their seatbelts or to wait a specified time before they could put the vehicle in gear. After collecting behavioral prebaseline data, a data logger was installed in all five vehicles to collect automated data on seatbelt use. Next the seatbelt-gearshift delay was introduced. The results showed that the delay increased all 5 drivers' seatbelt use, and that the duration of the delay that produced relatively consistent seatbelt use varied across drivers from 5 to 20 s. When the device was deactivated in four of the five vehicles, behavior returned to baseline levels.

Reducing conflicts between motor vehicles and pedestrians: the separate and combined effects of pavement markings and a sign prompt

The effects of a symbolic "yield here to pedestrians" sign and advance yield pavement markings on pedestrian/motor vehicle conflicts, motorists' yielding behavior, and the distance motorists' yield in advance of crosswalks were evaluated at multilane crosswalks at uncontrolled T intersections. In Experiment 1, the sign, when used alone, reduced pedestrian/motor vehicle conflicts and increased motorist yielding distance. The use of fluorescent yellow-green sheeting as the background of the sign did not increase the effectiveness of the sign. Further reductions in pedestrian/motor vehicle conflicts and further increases in yielding distance were associated with the addition of advance yield pavement markings. In Experiment 2, advance yield pavement markings, when used alone, were as effective in reducing pedestrian/motor vehicle conflicts and increasing yielding distance as the sign combined with pavement markings. These data suggest that the pavement markings were the essential component for reducing conflicts and increasing yielding distance.

Effects of a driver enforcement program on yielding to pedestrians

A driver-yielding enforcement program that included decoy pedestrians, feedback flyers, written and verbal warnings, and saturation enforcement for a 2-week period was evaluated in the city of Miami Beach using a multiple baseline design. During baseline, data were collected at crosswalks along two major corridors. Treatment was introduced first at selected crosswalks without traffic signals along one corridor. A week later, enforcement was shifted to crosswalks along the second corridor. Results indicated that the percentage of drivers yielding to pedestrians increased following the introduction of the enforcement program in each corridor and that these increases were sustained for a period of a year with minimal additional enforcement. The effects also generalized somewhat to untreated crosswalks in both corridors, as well as to crosswalks with traffic signals.

A study to measure the incidence of driving under suspension in the Greater Moncton area

Roadside checkpoints were used to determine the percentage of motorists driving while suspended (DWS) during various times of the day. These data showed that the percentage of motorists DWS was 57% of the expected value relative to their representation among all drivers. Data also showed that suspended drivers make up a higher percentage of drivers on the road after midnight. Results also indicated that 90% of suspended drivers stopped in this study produced a driving permit even though they are required to surrender it when suspended. In order to compare data collected at roadside checkpoints with self-report data. a questionnaire was administered to 456 persons taking a re-education course for first offenders and 68 participants taking a re-education course for second offenders. The results indicated that participants under-represented their own incidence of DWS. However, when asked about the driving behavior of other suspended drivers, their estimates were much closer to the data obtained with the roadside survey.