We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Driver tolerance of lateral accelerations on horizontal curves.
- Authors
Hildebrand, Eric D.; Lewis, Jonathan
- Abstract
There are many roadways where existing horizontal curves fail to meet minimum geometric design standards for financial or geographic reasons. Advisory speeds, typically set with a ball-bank indicator, are posted on these curves to ensure that drivers are not subjected to uncomfortable levels of lateral accelerations as they negotiate the curve. The threshold levels of lateral acceleration as estimated by ball-bank indicators vary considerably between jurisdictions with many still basing their guidelines on studies dating back to the 1930s and 1940s. This study investigated present day ball-bank indicator tolerance levels by analyzing actual driver behaviour on 30 curves posted with advisory speeds in New Brunswick. A unique method of data collection involving digital video analysis enabled the development of vehicle speed profiles approaching and throughout the curves. The results indicated that drivers tolerate higher levels of discomfort as they navigate curves than currently assumed. This finding justifies raising the ball-bank indicator threshold levels used for posting advisory speeds. Inconsistencies between actual posted advisory speeds, policy guidelines, and jurisdictional implementation have also been identified. Recommendations address both short and long-term goals of updating ball-bank indicator thresholds used for signing to levels that better represent driver behaviour. Longer-term recommendations address the development of uniform signing standards across Canada so that driver expectation will not be violated between jurisdictions.
- Subjects
ROAD construction; AUTOMOBILE laws; TRAFFIC safety; SIGNAGE; SPEED humps
- Publication
Canadian Journal of Civil Engineering, 2010, Vol 37, Issue 3, p413
- ISSN
0315-1468
- Publication type
Article
- DOI
10.1139/L09-164