Developing a Measure of Traffic Calming Associated with Elementary School Students' Active Transport

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

Active school transport in an urban environment:prevalence and perceived barriers

BACKGROUND

Active school transport (AST) can increase children's and adolescents' physical activity. The proportion of children and adolescents who engage in AST has declined internationally in recent decades. This study examines the prevalence, correlates, and perceived barriers to AST in the city of Leipzig, Germany.

METHODS

The study sample includes 1070 participants, 364 children and 706 adolescents, aged between 6 and 18 years, as well as their parents. The parents as well as adolescents age 10 and above completed questionnaires concerning sociodemographic variables, means of transport/AST and perceived barriers to AST. The distance between home and school was calculated as the network distance from the home to school address using the Dijkstra algorithm. Based on these data, logistic models were fitted in a two-step variable selection process, using AST as the dependent variable.

RESULTS

Approximately half of the children (59%) and adolescents (51%) engaged in AST. The prevalence of AST exhibited a negative correlation with age (Odds Ratio (OR) = 0.94, 95% confidence interval (CI) = 0.9-0.99, p = 0.015) and did not significantly differ by gender (children: OR_girls = 1.5, CI = 0.95-2.25, p = 0.075, adolescents: OR_girls = 1.01, CI = 0.75-1.37, p = 0.924). A high socioeconomic status was positively correlated to AST on the morning trip (OR = 1.7, CI 1.3-2.21, p < 0.01) but negatively on the afternoon trip (OR = 0.7, CI = 0.53-0.9, p < 0.01) in the summer. Common barriers for children (from their parents' perspective) and for adolescents (from their own and their parents' perspective) were distance and a heavy load to carry. The parents of adolescents did not perceive any other specific barriers as a serious impediment. Further significant barriers perceived by the younger children's parents were adults giving a lift on the way to other errands, no other children to walk or cycle with, and too much traffic. Too much traffic was also a significant barrier for adolescents, as were taking too much time and bad weather conditions.

CONCLUSIONS

Future interventions promoting AST in an urban environment should be guided by the identified perceived barriers.

TRIAL REGISTRATION

LIFE Child has been retrospectively registered with ClinicalTrials.gov (NCT02550236).

Integrating health indicators into urban and transport planning: A narrative literature review and participatory process

Today, urban and transport planners face considerable challenges in designing and retrofitting cities that are prepared for increasing urban populations, and their service and mobility needs. When it comes to health-promoting urban and transport developments, there is also a lack of standardized, quantitative indicators to guide the integration of health components right from the outset, i.e. in the formal planning or zoning phase. We narratively reviewed the literature and organized stakeholder workshops to identify and tailor planning principles and indicators that can be linked to health outcomes. We defined four core planning objectives that previous authoritative studies have suggested to result in positive health outcomes among city dwellers, which are: I) development of compact cities, II) reduction of private motorized transport, III) promotion of active (i.e. walking and cycling) and public transport, IV) development of green and public open space. Built on the review and stakeholder consensus, we identified 10 urban and transport planning principles that work towards achieving the four core objectives thought to provide health benefits for European city dwellers. These 10 planning principles are: 1) land use mix, 2) street connectivity, 3) density, 4) motorized transport reductions, 5) walking, 6) cycling, 7) public transport, 8) multi-modality, 9) green and public open space, and 10) integration of all planning principles. A set of indicators was developed and tailored for each planning principle. The final output of this work is a checklist ready to be applied by urban and transport professionals to integrate health into urban and transport developments in urban environments right from the outset.

Does Pedestrian Danger Mediate the Relationship between Local Walkability and Active Travel to Work?

BACKGROUND

Environmental and policy factors play an important role in influencing people's lifestyles, physical activity (PA), and risks for developing obesity. Research suggests that more walkable communities are needed to sustain lifelong PA behavior, but there is a need to determine what local built environment features facilitate making being active the easy choice.

PURPOSE

This county-level study examined the association between local walkability (walkability and traffic calming scales), pedestrian danger, and the percent of adults who used active transport to work.

METHODS

Built environment and PA outcome measures were constructed for the 496 most populous counties representing 74% of the U.S. population. Geographic information system-based walkability scales were constructed and include a census of roads located within the counties using 2011 Navteq data. The pedestrian danger index (PDI) includes data collected from the Fatality Analysis Reporting System 2009-2011, and measures the likelihood of a pedestrian being hit and killed by a vehicle. Four continuous outcome measures were constructed using 2009-2013 American Community Survey county-level 5-year estimates. The measures represent the percentage of workers living in a county who worked away from home and (1) walked to work; (2) biked to work; (3) took public transit; and (4) used any form of active transport. Linear regression and mediation analyses were conducted to examine the association between walkability, PDI, and active transport. Models accounted for clustering within state with robust SEs, and controlled for median household income, families with children in poverty, race, ethnicity, urbanicity, and region.

RESULTS

The walkability scale was significantly negatively associated with the PDI (β = -0.06, 95% CI = -0.111, -0.002). In all models, the PDI was significantly negatively associated with all active travel-related outcomes at the p < 0.01 level. The walkability scale was positively associated with all four outcomes at the p < 0.01 level. Results showed that the significant positive relationship between local walkability and the four active transport outcome measures was partially mediated by the PDI. We found no association between traffic calming, the PDI, and the active transport outcomes.

CONCLUSION

Results from this study show that, at the county-level, walkability is associated with active travel, and this association is partially mediated by an index of pedestrian safety.