Guidebook on Identification of High Pedestrian Crash Locations

CHAPTER 6. PRIORITIZE SITES

OVERVIEW

The selected performance measures and screening methods can be applied to the study network, resulting in a list of sites identified with the potential for safety improvement. These sites can then be ordered such that the sites with the most crashes are at the top of the list. Applying multiple performance measures to the same dataset can improve the certainty that the identified sites represent the locations with the most potential for improving pedestrian safety. While a simple ranking of sites by the performance measures will give the potential list of sites to be considered for treatments, the list can be adjusted by several factors.

ADJUSTMENTS

Factors that may be used to adjust the ranking of high crash locations or to select specific sites from a list of high crash locations include the following:

• Input from other stakeholders in the area (e.g., schools or the metropolitan planning organization).
• Planned maintenance (e.g., pavement overlay) that would permit implementation of a countermeasure that could treat the identified safety concern.
• Anticipated work by the State.
• Federal or State mandates.
• Available funding for specific countermeasures (e.g., distracted driving education campaign).

Priorities within a community could also affect the identification of candidate sites. For example, if the community wants to improve walkability, then street classification (e.g., collector streets may be given a higher priority than residential streets) or proximity to pedestrian generators (such as light rail transit stations, schools, parks and parkways, libraries, or neighborhood destinations) may be additional factors to consider. For example, some cities may pair the need to improve pedestrian safety with the need to encourage the community to walk more. Therefore, those cities may consider sites with the greatest potential to increase walkability among all sites with similar potential to improve pedestrian safety.

The process of identifying sites for treatment could include performing additional reviews of the sites. These reviews could use available aerial photographs or in-field reviews that would help identify roadway conditions. The results of these reviews could move a site higher or lower on the ranking list or could remove it from the list.

The prioritizing of sites may be conducted uniquely by location type. The ranking may be performed by geographical regions within a city so that all parts of the city receive some safety and infrastructure improvements rather than have all funding being directed to only one area within a city.

TOOLS

Tools are available to help with the ranking of sites, including the recently published APT (NCHRP Report 803).⁽²⁵⁾ APT presents a step-by-step methodology for prioritizing pedestrian and bicycle improvements along existing roads. It is designed to encourage practitioners to prioritize pedestrian and bicycle improvement locations by establishing a clear prioritization process.

EXAMPLES

New York City identifies priority lists using three categories: area (crashes/mi²), facilities (crashes/mi, but facility must be a minimum of 1 mi), and intersections. The city bases its lists on 5 yr of data. When identifying potential locations for treatment, it identifies areas and facilities until it has listed about 50 percent of a borough. The lists are generated per borough (Manhattan, the Bronx, Queens, Brooklyn, and Staten Island) to ensure that each borough receives some improvements. For intersections, the city limits the list to about 15 percent of the borough to obtain a manageable list (about 5,500 intersections for the entire city).

Portland, OR, identified the top 20 high crash streets for driving, bicycling, and walking. The combination of those sites resulted in 30 streets being on the high crash network. The motor vehicle network included the streets with the highest number of people killed or seriously injured for the years between 2004 and 2013. The bicycle and pedestrian networks included streets with the highest crash frequency, regardless of severity, for people bicycling and walking, respectively, in recognition that the difference between a minor and a serious injury for pedestrian or bicyclists is “often random and circumstantial.”⁽²⁷⁾ The number of 20 per mode (30 total) was selected as representing a balance between having enough streets to capture most of the fatal crashes (8 percent of streets capturing 56 percent of traffic deaths) and not having so many that the evaluation and countermeasure implementation steps far exceeded the ability to secure necessary resources.

SURROGATES

Because crashes can be rare events, some agencies have considered surrogates. Surrogates mentioned include the following:

• Location of activity centers.
• Type of land use, including when an apartment complex is across a major street from a grocery store.
• Retail or population density.
• Transit, such as location of bus stop or rail stations with respect to origins or destinations or number of riders (on or off).
• Number of lanes in combination with operating speed.
• Score that reflects the walkability of a street.
• Citizens’ comments.

Most surrogates are good indicators of locations with potential for pedestrian crashes because they are also reliable indicators of pedestrian traffic. Therefore, some agencies may collect surrogates not only to identify crashes but also to monitor and anticipate pedestrian volumes as well as to evaluate the walkability of sites.

Although surrogates have been considered, the number of crashes involving pedestrians is the key metric being used because of the emphasis on data-driven decisions.