Support for the development and implementation of an access management program through research and analysis of collision data : final report.
-
2015-11-11
-
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Edition:Final report
-
Corporate Publisher:
-
Abstract:The South Carolina Access and Roadside Management Standards (ARMS) provides standards and guidelines for
permitting access encroachments onto SCDOT right-of-way. In April, 2013, SCDOT initiated research that would be
used to update this manual with the intent that recommended changes could result in a reduction in crashes, injuries, and
fatalities on South Carolina roadways. The research examined current and historical practices used by other
transportation agencies with regard to access management. Using empirical data collected along several corridors that
ranked highest in driveway related crashes, the researchers statistically analyzed and identified the correlation of access
issues with crash data. Crash data were associated with driveways using complex Geographic Information System (GIS)
modeling tools. The statistical analysis identified several significant independent variables that influence crash rates
either positively or negatively. The results indicate that increasing the distance between driveways, increasing the
number of entry lanes, and having a raised median will decrease driveway related crashes. Conversely, increasing
driveway width, corridor volume and corridor speed limit will increase crashes. Similarly, a driveway with high
turnover land use, a driveway with full access (as opposed to right-in right-out), and the presence of nearby signalized
intersections will increase crashes. A micro-simulation analysis was used to investigate the operational performance of
different driveway spacing policies adopted by various DOTs in the US. Experimental results indicate that driveway
spacing has direct influence on the average travel speed of a corridor. Since reduced driveway spacing negatively
impacts corridor travel speed, selection of a minimum spacing should consider its effect on the operational performance
of the corridor. Benefit-cost analyses of two different access modification strategies following the Highway Safety
Manual (HSM) procedures suggest that it is beneficial to convert a TWLTL to a raised median. Similarly, it is beneficial
to reduce the driveway density on a corridor. The research also reviewed SCDOT access waiver procedures. While the
current process suffices based on our literature review it is evident that this process could be significantly streamlined
and enhanced with a paperless system. Based on research findings, recommended changes to SCDOT Access and
Roadside Management Standards (ARMS) are presented. It is anticipated that implementation of the findings of this
research will result in long-term economic benefits, and improved traffic flow and safety.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type: