Head-On Collisions: Appendix 1

Profiles of State and Local Implementation Efforts: Strategies 18.1 A1 and 18.1 B2 (Maryland State Highway Administration)

Emphasis Area
18.1-Reducing accidents involving head-on collisions

Objectives
18.1 A-Keep vehicles from encroaching into opposite lane
18.1 B-Minimize the likelihood of crashing into an oncoming vehicle

Strategies
18.1 A1-Install centerline rumble strips for two-lane roads
18.1 B2-Install median barriers for narrow-width medians on multilane roads

Agency and Jurisdiction
Maryland State Highway Administration

Problem(s) Identified
Maryland was experiencing excessive rates of fatal head-on collisions at certain two-lane road locations.

Goals and Objectives Established
To reduce the rate of head-on collisions at such locations.

Description of Strategies Implemented
Maryland implemented a series of treatments to reduce head-on crashes at different locations. These included the use of flexible posts, raised pavement markers (RPMs) and rumble strips on the centerline, and the development of a narrow (4-8 ft) buffer medians containing a median guardrail.

Summary of Implementation Effort
First, in 1998, a 0.56-mile section of MD 410 was modified to include flexible posts on the centerline of the roadway. A before/after study of the site indicated a decrease in rear-end crash rates, essentially no change in opposite direction crashes, and an increase in sideswipe and fixed object crashes. It is noted that the number of crashes analyzed was fairly small.

In a much more major effort, the Maryland DOT began a correction program aimed at head-on crashes on 11.91 miles of MD 90, a limited-access two-lane road. The first phase involved the installation of raised pavement markers on the centerline. While nighttime crash rates appeared to decrease some, the head-on problem was not solved to Maryland's satisfaction. In 1988, centerline rumble strips were added. Again, the before/after study indicated some decreases in crash rates, but more was desired in certain sections. In 1996, in an experimental effort, a buffer median was developed on 6.23 miles of this 12-mile section, and a median guardrail was installed in this median. The curbed median width varied from 4 to 10 ft and was developed from existing ROR and paving (narrowing the shoulders). While the samples of crashes are again small, a before/after study indicated that the head-on rate decreased approximately 50 percent in a 1-year after period. A similar treatment (buffer median with barrier) was applied to a 0.68-mile section of MD 140 in 1994. Again, head-on rates improved significantly (but the numbers are small).

It should be noted that both MD 90 and MD 140 are not standard rural two-lane roads. They had partial access control (no driveways), and the junctions were primarily interchanges. Only a limited number of at-grade intersections existed on these sections of roadway. One of the routes is primarily a recreational route providing access to eastern-shore beaches, whereas the other is a suburban arterial.

Contact Person and Information
Manu Shah, Chief, Traffic Safety, MD State Highway Administration, 410-787-5825, Mshah@sha.state.md.us