United States Department of Transportation
i
Technical Guidance to Support Local Computation of VMT-based Safety Performance Targets
-
2016-03-15
-
Series: Memoranda & Guidance: Guidance
[PDF-58.83 KB]
Details:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Series:
-
Resource Type:
-
Right Statement:
-
Geographical Coverage:
-
Corporate Publisher:
-
Abstract:23 U.S.C 150, requires States to establish safety performance targets, and 23 U.S.C 134 requires Metropolitan Planning Organizations (MPOs) to also establish safety targets within 180 days of the State’s target. The Safety Performance Measures (PM) regulation under 23 CFR 490.209 allows MPOs, in setting targets, to either agree to plan and program safety projects so that they contribute toward the accomplishment of the State DOT targets, or to commit to quantifiable targets for the entire Metropolitan Planning Area. The regulation under 23 CFR 490.207, defines two Vehicle Miles Traveled (VMT) rate-based safety performance measures: Rate of Fatalities per 100 Million VMT and Rate of Serious Injuries per 100 Million VMT. The performance measures are defined as a 5 year rolling average, based on the most recent five years for which data is available. Whereas States are expected to use Highway Performance Monitoring System (HPMS) data to furnish the VMT denominator for the safety rate metrics, using HPMS data at the MPO level is not directly possible. The VMT denominator must include travel on all public roadways within the Metropolitan Planning Area boundary. In HPMS, local roadway travel is reported in aggregate for the state and for large Census urbanized areas. However, urbanized areas do not necessarily coincide with Metropolitan Planning Area boundaries, as MPOs must also plan for areas that are reasonably expected to become urbanized in the next 20 years. In HPMS, travel on roadways with higher functional classification is reported for specific geo-located roadway segments and may be readily disaggregated to the geographic bounds of a Metropolitan Planning Area. However, because travel on local roadways is not geo-located, HPMS by itself does not provide sufficient information to compute full travel in an MPO study area. The present guidance is offered to identify reasonable technical methods for developing consistent VMT estimates on local roadways for a geographic area smaller than an entire State. In addition to reporting historical data, MPOs (and States) may wish to extrapolate estimates of VMT when establishing their performance targets for the subsequent calendar year. A variety of extrapolation techniques are available. These include simple trend line analysis, more complex regression models that take account of unique circumstances that differ from the historical trend, and application of regional travel demand models that extrapolate from behavioral estimates rather than direct traffic observation. Both States and MPOs may reasonably be expected to apply some or all of these methods. The present guidance thus suggests minimal extrapolation methods that can be used to estimate VMT, and guidelines for establishing the suitability of more elaborate methods.
-
Format:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
