We can use ITS to:
- Move traffic more effectively.
- Manage traffic using "smart signals" that responds to the needs of travelers.
- Help clear traffic incidents more quickly.
- Provide better information to travelers about road conditions.
- Reduce traffic maintenance costs.
- Improve transportation system efficiency.
ITS cannot:
- Increase road capacity
- Eliminate traffic congestion
Over-height detection system reducing bridge strikes
No large trucks have struck or gotten stuck under the railroad bridge overpass on Grahams Ferry Road since the installation of the updated over-height detection system in 2022.
The $250,000 system, funded by Washington County and TriMet, is located on either side of the bridge on Grahams Ferry Road, between Clutter Road and the Washington/Clackamas County line. The bridge has only 12.5 feet of clearance and is used by TriMet’s WES commuter rail during rush hours. Between 2011-2022, there were 33 bridge strikes reported.
“These crashes were becoming more frequent, expensive and time consuming for TriMet, freight customers and travelers,” said Stacy Shetler, County Engineer, Washington County Land Use & Transportation.
“When the bridge is struck, both the bridge and Grahams Ferry Road had to close. TriMet has to have a bus drive WES passengers around the bridge. The trucks and cargo are damaged, and debris is strewn all over the road. Our inspectors, (Union Pacific) railroad inspectors and TriMet all have to check the bridge and rail for damage. It’s expensive and potentially catastrophic.”
The new system uses lasers to detect over-height vehicles on Grahams Ferry Road which activate warnings. There are two types of detection zones:
- The primary detection zones include flashing lights, warning signs and lights. There zones are on Grahams Ferry Road, both north and south of the bridge, and on Clutter, east of the intersection with Grahams Ferry. Drivers are directed to use alternate routes.
- The secondary detection zone includes a second set of lights, signs, a loud horn and overhanging chains that drag across the top of the vehicle. This zone is between Clutter Road and the bridge. If trucks reach this point, drivers have to back up.
“It would be hard for a driver to miss the warnings and hanging chains,” Shetler said. “We haven’t had any bridge strikes in three years, so it appears the system is working.”
The system also logs over-height vehicle activations and can notify TriMet and County staff of warning system activations via text or email. The system also includes traffic cameras that allow staff to monitor the locations.
The $250,000 cost of the system was shared equally by TriMet and Washington County. Washington County’s portion was funded with Intelligent Transportation System (ITS) Gain Share Funds.
“The cost of raising the bridge or lowering the road would have been millions,” Shetler said. “This over-height detection system is a good value for the investment.”
What is an ITS Plan?
The ITS Plan is a technical document. It includes the policy and process for using ITS to improve travel in our County.
Contact(s)
Name | Title | Phone | |
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Heather Sturgill
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Senior Communications Specialist/PIO
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