Study Details

Study Title: Modeling and Evaluating the Safety Impacts of Access Management (AM) Features in the Las Vegas Valley

Authors: Mauga and Kaseko

Publication Date: JAN, 2010

Abstract: This paper presents results of a study that developed statistical models that relate access management (AM) features with traffic safety in midblock sections of street segments. The objective of the study was to evaluate and quantify the impact of the AM features on traffic safety in the midblock sections. It is anticipated that the results of this study will assist local jurisdictions in the Las Vegas valley in the development of new AM policies and programs. Models were calibrated for two main types of median treatments for street segments, namely, raised medians (RM) and two-way-left-turn-lanes (TWLTL). Other AM features considered were signal spacing and the densities of driveways, median openings and unsignalized cross roads. Separate models were developed for the impacts on total crash rates, types of crashes and severity. The study results confirmed the intuitive expectation that these AM features do have significant impact on safety. They show that segments with RM had lower crash rate by 23% compared to segments with TWLTL. The results also show that higher densities of driveways cross roads and median openings results in higher crash rates and severity. For example, for segments with RM, each additional median opening per mile results in a 4.7% increase in the total crash rate. A comparison of these results with pervious similar studies is also made in this paper.

Study Citation: Mauga, T. and Kaseko, M., "Modeling and Evaluating the Safety Impacts of Access Management (AM) Features in the Las Vegas Valley." Transportation Research Record: Journal of the Transportation Research Board 2171, pp. 57-65, 2010


CMFs Associated With This Study

Category: Access management

Countermeasure: Change in driveway density from X to Y driveways per mile

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle All All Urban
CMF Equation CRF Equation 3 Stars Angle All All Urban
CMF Equation CRF Equation 3 Stars Rear end All All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle A,B,C All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle O All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle All All Urban
CMF Equation CRF Equation 3 Stars Angle All All Urban
CMF Equation CRF Equation 3 Stars Rear end All All Urban
CMF Equation CRF Equation 3 Stars Sideswipe All All Urban
CMF Equation CRF Equation 3 Stars Fixed object,Run off road,Single vehicle All All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle A,B,C All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle O All Urban

Countermeasure: Change in median opening density from X to Y median openings

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle All All Urban
CMF Equation CRF Equation 3 Stars Angle All All Urban
CMF Equation CRF Equation 3 Stars Head on All All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle A,B,C All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle O All Urban

Countermeasure: Change in signal spacing from X 1000's feet to Y 1000's feet

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle All All Urban
CMF Equation CRF Equation 3 Stars Rear end All All Urban
CMF Equation CRF Equation 3 Stars Sideswipe All All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle All All Urban
CMF Equation CRF Equation 3 Stars Rear end All All Urban
CMF Equation CRF Equation 3 Stars Fixed object,Run off road,Single vehicle All All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle O All Urban

Countermeasure: Change in unsignalized cross roads from X to Y unsignalized cross roads per mile

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
CMF Equation CRF Equation 3 Stars Sideswipe All All Urban
CMF Equation CRF Equation 3 Stars Fixed object,Run off road,Single vehicle All All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle All All Urban
CMF Equation CRF Equation 3 Stars Rear end All All Urban
CMF Equation CRF Equation 3 Stars Sideswipe All All Urban
CMF Equation CRF Equation 3 Stars Head on All All Urban
CMF Equation CRF Equation 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle A,B,C All Urban

Countermeasure: Replace TWLTL with raised median

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
0.77 23 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle All All Urban
0.65 36 3 Stars Angle All All Urban
0.81 19 3 Stars Rear end All All Urban
0.79 21 3 Stars Sideswipe All All Urban
0.53 47 3 Stars Head on All All
0.79 21 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle A,B,C All Urban
0.67 33 3 Stars Angle,Fixed object,Head on,Rear end,Run off road,Sideswipe,Single vehicle O All Urban