Emphasis Area -- Run-off-road Crashes

 

Strategy Number and Name – Multiple strategies including bicycle-friendly rumble strips, edgeline rumble strips, and innovative curve markings.

 

Agency and Jurisdiction -- Pennsylvania DOT.

 

Problem(s) Identified -- Increased rates and frequencies of run-off-road or head-on crashes on two-lane roads.

 

Goals and Objectives Established – Reduce these crash rates, while continuing to better serve other users such as bicyclists.

 

Description of Strategy(ies) Implemented --

  1. Bicycle-friendly rumble strips --- Working for the Pennsylvania DOT, the Pennsylvania Transportation Institute conducted research on alternative designs to alert motorists while being disruptive to the bicyclist. The resulting design, which is used on shoulders at least 6 feet wide, is a 3/8-inch-deep cut that is 5 inches wide with a 7-inch space between cuts. The rumble strips begin 6 inches off the edge of pavement. (http://cta.pti.psu.edu/projects/rumble.html)

  2. Edgeline rumble strips on two-lane roads with 4-ft shoulders

  3. "SLOW/arrow" curve warning treatment to reduce speeds at hazardous curves

 

Summary of Implementation Effort --

  1. Bicycle-friendly rumble strips – These are being implemented at selected locations in the summer, 2001.

  2. Edgeline rumble strips – On sections with 4-ft shoulders, Pennsylvania is trying experimental installations of rumble strips on and near the edgeline (rather than further out on the shoulder). These are milled–in continuous strips approximately 7" apart, 5" inches wide and 0.25 in. deep.

  3. Working with the Insurance Institute for Highway Safety, PA DOT installed an experimental warning design on the pavement at six curves. (The same treatment had been installed earlier at one site in Northern Virginia.) The treatment consists of the word "SLOW" in 8-foot-high white letters, a white 8-foot-high left curve arrow, and an 18-inch-wide white line perpendicular to the road at the beginning and end of the text/symbol. In 2001, the marking will be implemented at 200 sites statewide.

 

Summary of Results --

  1. Bicycle-friendly rumble strips – Current installation, with no results at this time.

  2. Edgeline rumble strips -- PA DOT has chosen locations (high hazard sites) and are beginning to install these in the spring and summer, 2001.

  3. "SLOW/arrow" curve-warning treatment – at the six curves where it was implemented, a before/after study of effects on vehicle speeds showed that these pavement markings had little effect on the average speed and the 85th percentile speed. However, the 95th percentile speed was reduced significantly.

Contact Person and Information – Mike Baglio, PA DOT Bureau of Highway Safety, 717-705-1706, mbaglio@dot.state.pa.us