Investigation of the Crashworthiness of
Barrier Mounted Hardware
Background
Recently completed research (1) has indicated that there is a "zone of intrusion" on and around commonly used traffic barriers. This zone of intrusion is the air space around a barrier into which impacting vehicles will likely penetrate. Hardware and other obstacles placed within this zone are then likely to be struck by an errant vehicle. Caltrans has recently become aware that some of the hardware currently being placed on various barriers throughout the State are within this zone of intrusion and therefore need to be investigated for crashworthiness. The list of hardware that can be found on the roads but has not been crash-tested to current crash test guidelines includes: high-occupancy vehicle (HOV) signs, glare screens, fences, speed limit signs, warning signs, etc. None of these items have been tested to current crash test standards. Furthermore, the vehicle fleet on the highway today contains many vehicles for which some of these hardware devices were not designed. There are insufficient crash test data to verify that these items will comply with National Cooperative Highway Research Program (NCHRP) Report 350 (2) criteria.
Example of Field Installation of Barrier Mounted Signs
Test 641: Metal Barrier Mounted Sign on Type 60 Concrete Median Barriers
Test 641, the first in a series of tests, was conducted using a Metal Barrier Sign typically used to mount HOV signs on Type 60 Concrete Median Barrier. The signpost is welded to a saddle that sits over the barrier and is fixed with two bolts. The purpose of this test is to record the effect the fixture has on the vehicle’s impact with the barrier and not the fixture itself. Test 641 meets the criteria for NCHRP Report 350 Test Level 3-11 for longitudinal barriers.
| Impact Conditions | ||
| Test Level: | NCHRP Report 350 Test 3-11 | |
| Vehicle: | 1993 Chevy Cheyenne ¾ Ton Standard Cab Pickup | |
| Impact Speed: | 100 km/h (62.1 mph) | |
| Impact Angle: | 25 Degrees | |
Vehicle Impact
Base Plate & Anchorage Details
References and Related Links
- Ronald K. Faller, Dean L. Sicking, et al, "Guidelines for Attachments to Bridge Rails and Median Barriers", Midwest States Regional Pooled Fund Research Program, February 26, 2003.
- Report 350
- Concrete Barrier Type 60 Standard Plan
- Sign R84-1 (CA)
Contact Information
- Christopher Caldwell
christopher.caldwell@dot.ca.gov
Project Engineer - John Jewell
john.jewell@dot.ca.gov
Senior Engineer - Bob Meline
bob.meline@dot.ca.gov
Senior Engineer