Centerline Turn Hardening
Image Source: Insurance Institute for Highway Safety (IIHS) and the Highway Loss Data Institute (HLDI)
DEFINITION AND DESCRIPTION
Centerline turn hardening entails installing features such as bollards and curbs to prevent drivers from cutting across intersections at a diagonal. They can improve pedestrian safety and address failure-to-yield crashes caused by left-turning vehicles by encouraging drivers to make left turns at slower speeds.
Implementation Categories
| Area(s) | Design & Geometrics, HSIP, Operations & Maintenance |
| Safety Category | 2 |
CONSIDERATIONS
- Check the turning path of the design vehicle.
- Determine acceptable materials (e.g., raised medians, lane separators, tubular markers, flexible delineators, rubber speed bumps) for centerline hardening.
- Stripe the border of curbs and rubber speed bumps yellow to increase their visibility.
- Delineators and pavement markings must comply with the MUTCD Part 3 .
- May require specialized material or equipment to maintain/replace.
- Potential for snowplow impacts on rubber curbs.
APPLICATION
- Use on intersections with high pedestrian and left-turn volumes or a history of pedestrian crashes.
- Up to the stop bar, hardening may consist of cast-in-place curbing materials, quick-build curbing materials, or pavement-mounted flexible tubular markers or delineators.
- An additional centerline treatment that extends curbing toward the intersection beyond the crosswalk may be used to further enhance safety.
example
Image Source: Insurance Institute for Highway Safety
Complimentary Countermeasures
- Leading Pedestrian Interval (LPI)
- Human Factors Guidance – Speed Calming Countermeasures at Crosswalks
REFERENCES AND RESOURCES
Insurance Institute for Highway Safety (IIHS) and the Highway Loss Data Institute (HLDI). Simple infrastructure changes make left turns safer for pedestrians. 2020. https://www.iihs.org/news/detail/simple-infrastructure-changes-make-left-turns-safer-for-pedestrians
New York City Department of Transportation. Turn Calming Program. https://www.nyc.gov/html/dot/html/pedestrians/turn-calming.shtml
CONTACT:
Jill Asher
Research Engineer
jill.asher@uky.edu