The National Academies

NCHRP 17-87 [Completed]

Enhancing Pedestrian Volume Estimation and Developing HCM Pedestrian Methodologies for Safe and Sustainable Communities

  Project Data
Funds: $550,000
Research Agency: Kittelson & Associates
Principal Investigator: Paul Ryus
Effective Date: 4/20/2018
Completion Date: 4/20/2020
Comments: To to be published as NCHRP WOD 312 and NCHRP Research Report 992

Status: Agency’s report documenting the entire project to be published as NCHRP WOD 312 and the Guide as NCHRP Research Report 992. The HCM chapters have been approved by the TRB Highway Capacity & Quality of Service Committee and will be included in the HCM version 6.1 update that will be published toward the end of the year.

In 2015, 5,376 pedestrians were killed and an estimated 70,000 were injured in traffic crashes in the United States (Traffic Safety Facts, NHTSA). Pedestrian deaths accounted for 15% of all traffic fatalities. While the majority of the fatalities occurred in urban areas, the fatality risk can be even higher in rural areas after controlling for exposure.  To address this growing problem, accurate methods for estimating pedestrian volumes are needed to quantify exposure, and, in turn, evaluate the benefits of pedestrian countermeasures. Counting pedestrians is challenging, and there is a need for tools that can usefully estimate exposure when counts are unavailable or are limited in coverage (e.g., over short time periods or in few locations).
Roadway designs and signal phasing that address the safety of all road users are being implemented in many cities around the country. These roadway designs include road diets, with corner bulb-outs and sidewalk extensions, addition of bike lanes, crosswalk widening, and addition of corner or median refuge areas. Currently, these treatments are not evaluated in the Highway Capacity Manual (HCM) pedestrian Level of Service (LOS) methodologies.

The objective of this research was to develop scalable guide for jurisdictions (urban, suburban, and rural) to: (1) identify techniques for efficient and accurate estimation of pedestrian volume and exposure; (2) determine field-observed factors affecting pedestrian flow at the facility levels and integrate those factors into the HCM pedestrian LOS methodology; (3) determine how pedestrian safety improvements on the roadway and in signal timing designs (e.g., sidewalk extensions, corner bulb-outs, implementing Leading Pedestrian Intervals (LPIs), and associated crash modification factors) should be reflected in the HCM pedestrian (LOS); and (4) recommend corresponding enhancements to the current HCM methodology.

The guide also should address issues related to pedestrian volume estimation, safety risk exposure, and the relationship between HCM pedestrian LOS measures and pedestrian safety, through investigations such as, but not limited to, the following:
  • Whether shy distances on sidewalks remain constant or if they fluctuate based on other factors (e.g., density, presence of counter flow, frequency of obstructions);
  • If there are other field-observed factors (e.g., crosswalk configurations, vehicle behaviors) that might affect the pedestrian crosswalk LOS;
  • Extensions to the HCM pedestrian LOS methodology to accurately assess impacts of improvements such as corner bulb-outs and other pedestrian safety and comfort enhancements; and
  • A review of pedestrian safety analysis methodologies (e.g., crash frequency, severity prediction) for a specific roadway design and compare with the HCM pedestrian LOS analysis results.

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