Study Details

Study Title: Correlating Access Management to Crash Rate, Severity, and Collision Type

Authors: Schultz et al.

Publication Date:JAN, 2008

Abstract: The safety and performance of arterial roads must be continually monitored to ensure that people and goods can be oved as efficiently and safely as possible. As access is provided along arterial roads, the potential for negative consequences to safety and performance has been demonstrated through factors such as decreased speed, decreased level of service, and more importantly, a reduction in safety. To help offset the negative consequences of access along an arterial roadway, access management techniques are implemented to control the location and operation of driveways and related street connections. The purpose of this paper is to summarize and discuss research performed to identify relationships between access management and the safety characteristics of arterial road segments to better quantify the effectiveness of access management principles and techniques. Statistical analysis, specifically stepwise linear regression, was used to determine correlations between access management techniques and crash histories including crash rate, crash severity, and collision type. Statistical analyses showed that the lack of access management, such as high access density, numerous signals per mile, and lack of medians, was positively correlated with increased crashes and severity. Furthermore, land use was identified to play a significant role in the safety of arterial roads as those arterial road segments with adjacent commercial land use tended to have higher crash rates and severity. Because of the link between access management and crash rates, severity, and collision type, access management should be continually utilized in the planning of new arterial roadways and the reconstruction of existing facilities.

Study Citation: Schultz, G.G., K.T. Braley, and T. Boschert, "Correlating Access Management to Crash Rate, Severity, and Collision Type." TRB 87th Annual Meeting Compendium of Papers CD-ROM. Washington, D.C., (2008).

CMFs Associated With This Study

Category: Access management

Countermeasure: Install raised median

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
0.2970.774 StarsAllAllPrincipal Arterial OtherUrban
0.4555.434 StarsAngleAllPrincipal Arterial OtherUrban

Category:Intersection traffic control

Countermeasure: Change traffic signal spacing from X to Y signals per mile

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
CMF EquationCRF Equation4 StarsAllAllPrincipal Arterial OtherUrban
CMF EquationCRF Equation4 StarsAngleAllPrincipal Arterial OtherUrban


Countermeasure: Commercial vs. residential land use

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
3.42-242.124 StarsAllAllPrincipal Arterial OtherUrban
1.77-774 StarsAngleAllPrincipal Arterial OtherUrban