The National Academies

NCHRP 17-97 [Anticipated]

Strategies to Improve Pedestrian Safety at Night

  Project Data
Source: AASHTO Committee on Safety
Funds: $500,000
Staff Responsibility: Inam Jawed
Fiscal Year: 2021

This project has been tentatively selected and a project statement (request for proposals) is expected in August 2020. The project statement will be available on this site. The problem statement below will be the starting point for a panel of experts to develop the project statement.

An estimated 6,227 pedestrians were killed in traffic collisions in the U.S. in 2018 – a 30.3% increase in pedestrian fatalities over the last five years and the highest number of pedestrians killed in one year since 1990. About 75 percent of these pedestrian fatalities occurred in darkness, and much of the recent increase in fatalities is driven by nighttime crashes. In fact, from 2008 to 2017, nighttime crashes accounted for more than 90 percent of the total increase in pedestrian deaths. Despite the magnitude of this problem, scant research focuses on the reasons for, and solutions to, this important and worrying nighttime trend. This study will identify and examine strategies to improve pedestrian safety in the dark and reduce nighttime pedestrian fatalities and severe injuries.

Pedestrians are at higher risk of a collision in the dark, all else being held equal. Severity of these nighttime collisions are worse than daytime crashes, with nighttime pedestrian collisions at intersections having an 83% higher chance of being fatal without street lighting and a 54% higher chance of being fatal with street lighting.

The reasons for this increased risk are not clear. Much research has been completed on vehicular headlighting and reflective clothing, finding that increased headlight sight distance and clothing conspicuity may improve pedestrian safety outcomes. However, this work was specific to vehicle lighting and reflective clothing and didn’t explore whether these issues are the principal cause of the collisions in the first place. Vehicle speed, limited-access roadways, and alcohol use by pedestrians have also been identified as issues. However, all these studies utilized data from 2004 or earlier, meaning that they don’t explain what has caused the substantial increase in nighttime pedestrian fatalities over the last ten years. Driver and pedestrian distraction and changing vehicle body types have also been suggested as possible explanations for the recent increase in pedestrian fatalities, but available data do not provide conclusive evidence for these connections. An on-going study in Virginia is developing guidelines for intersection and mid-block pedestrian crossing lighting design and warrants for use by the Virginia Department of Transportation, but a better understanding the role of lighting level plays relative to other causal factors would be warranted. 

The objective of this research is to identify and evaluate strategies for improving pedestrian safety in the dark. To accomplish this, the research will begin by reviewing root causes of pedestrian-involved fatalities and severe injuries, and then evaluate existing strategies and research regarding nighttime pedestrian safety. It will then explore fatal and non-fatal pedestrian crashes to identify unique patterns in nighttime pedestrian crashes and safety outcomes. These patterns may be related to roadway or facility design, vehicle characteristics, user socio-economics or behavior, etc. With these patterns in mind, the research will propose solutions for the problems identified. Possible strategies may include interventions related to engineering (e.g. enhanced crossings, lighting, etc.), enforcement (e.g. distraction, alcohol use, etc.), and education (e.g. if certain populations are more impacted than others), depending on the patterns revealed in the research. These proposals may be tested with future research.

Specific research tasks may include:
1. Literature review of existing strategies and research regarding nighttime pedestrian safety issues leading to severe injuries and fatalities
2. Data collection (crash, roadway environment such as lighting, geometry, facilities, operational details, users, vehicles, etc.)
3. Identify safety patterns related to exposure (pedestrian and vehicle volumes), roadway or facility design, roadway lighting, traffic operations, vehicle characteristics, user socio-economics or behavior
4. Propose solutions to be investigated in future research

This research is an urgent need, as it seeks to reverse the worrying trend of nighttime pedestrian fatalities and severe injuries. The trend is found throughout the country and will be of high interest to a majority of DOTs as well as regional and local agencies. Arizona and Connecticut DOTs have specifically identified this as a high priority focus area. Findings will also serve to greatly improve overall pedestrian safety, with benefits directly to some of the most vulnerable users of our roads.

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