When are curve and turn signs required?
For all collectors and arterials with more than 1,000 vehicles per day, curve and turn signs need to be in compliance with FHWA guidelines by the end of 2019. While that is over a year away, we know it takes time to get the curves properly studied and the signs ordered and installed.
According to the MUTCD, arrows or chevron shall be used if the difference between the advisory speed and the speed limit is 15 mph or more on arterials and collectors with more than 1,000 AADT. On roads classified as local and arterials and collectors with less than 1,000 AADT, arrows or chevrons may be used if engineering judgment dictates there is a need. An engineering study should be done to confirm the proper signs to be used for all curves and turns.
Here is a simplified version of Table 2C-5 that shows the critical issues:
Horizontal Alignment Sign Selection for Arterials and Collectors with AADT more than 1,000 vehicles per day
We have listed some resources to determine traffic volume and if a highway is an arterial or collector below.
Resources:
- 2017 Traffic Sign Handbook
https://cornell.app.box.com/v/clrp-pb-tsh - CLRP NYS MUTCD Page
http://www.clrp.cornell.edu/assistance/mutcd-info.html - Table I-2. Target Compliance Dates Established by FHWA
https://mutcd.fhwa.dot.gov/htm/2009r1r2/intro/intro.htm#tableI02 - Table 2C-5. Horizontal Alignment Sign Selection
https://mutcd.fhwa.dot.gov/htm/2009r1r2/part2/part2c.htm#table2C05 - How can I get a quick estimate of traffic volume on my highways without traffic counters or a speed trailer?
http://www.clrp.cornell.edu/q-a/212-TrafficCounts.html - How can I find out the official functional class of a highway?
https://www.clrp.cornell.edu/q-a/191-functional.html
