Safety effects of part-time signals?
Safety effects of part-time signals?
(OP)
On one of our arterials (3 lane, 30 mph, ADT = ~15,000) the detection has failed on a signal serving an office park. We've been getting complants about unnecessary delays due to the sideroad being on recall.
Little traffic comes out of the sideroad after about 6 PM. Several people have suggested putting the signal on flash at night. Has any research been done concerning whether the increased risk of right-angle crashes outweighs the reduction in delay?
This road is due for reconstruction in 2009, so we are loath to make the permittee spend a lot to fix the detection on a signal that may be rebuilt or even replaced by a roundabout in 2 years.
Little traffic comes out of the sideroad after about 6 PM. Several people have suggested putting the signal on flash at night. Has any research been done concerning whether the increased risk of right-angle crashes outweighs the reduction in delay?
This road is due for reconstruction in 2009, so we are loath to make the permittee spend a lot to fix the detection on a signal that may be rebuilt or even replaced by a roundabout in 2 years.
"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928
"I'm searching for the questions, so my answers will make sense." - Stephen Brust





RE: Safety effects of part-time signals?
RE: Safety effects of part-time signals?
NCHRP REPORT 457: Engineering Study Guide for Evaluating Intersection Improvements, p. 13:
and Abdelghany and Connor, (Guidelines for Operating Traffic Signals during Low-Volume Conditions, p. 30: http:
They go on to recommend that, after considering sight distance, speed, crash history, etc, red/yellow flash may be used during hours when the volumes would work with TWSC, and red/red flash could be used when AWSC would work.
"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928
"I'm searching for the questions, so my answers will make sense." - Stephen Brust