Wavetronix

TxDOT has deployed a system to alert truck drivers when they exceed the safe, posted speed limit on freeway ramps. The goal is to reduce the number of semi-truck rollovers that occur when truck drivers attempt to negotiate the ramps at unsafe speeds.Magdy Kozman, transportation operations engineer at TxDOT, says there was considerable trouble on tight interchange connector ramps around Houston. “There were high instances of trucks rolling over due to excessive speed, unknown cargo loading factors, and freeway super elevation problems,” Kozman says. TxDOT needed a non-intrusive solution because their previous loop system required a traffic control plan to close the ramp for installation. It also needed to get creative with methods of alerting drivers. “The flashing system was a challenge because no other similar application existed to our knowledge,” Kozman says.

The Oregon Department of Transportation has implemented an advance warning system that alerts drivers entering a tunnel to the presence of slow or stopped traffic at the tunnel’s exit. The system uses a combination of SmartSensor Advance and Matrix units to detect traffic; if certain conditions exist, the system activates a flashing sign that warns drivers to slow down.Transportation officials in Oregon were faced with a dangerous traffic situation at the interchange between Interstate 84 and Interstate 205 east of Portland: a significant number of rear-end collisions were occurring because drivers were unaware that traffic ahead of them had slowed or stopped. The problem occurred at a tunnel that drivers must enter to merge from westbound I-84 onto southbound I-205. There is a sharp left turn just after the tunnel and traffic often backs up to the tunnel exit, particularly during peak congestion times. Drivers entering the tunnel at full speed were unaware of conditions ahead of them, and could not see stopped traffic around the turn.

US Highway 2 at Kalispell, Montana, features a dangerous, non-signalized intersection that has been the site of numerous crashes. The two-lane, high-speed highway intersects with Springcreek Road/Dern Road and has no turn lane. The goal of the project was to improve safety at the intersection without adding lanes or installing signals. Because there is no turn lane, when eastbound cars need to turn left onto Springcreek Road they are forced to stop in the lane of travel and hope that cars approaching from behind see them and stop in time. Unfortunately, too many drivers didn’t see the stopped vehicles until it was too late, resulting in numerous crashes. The posted speed limit on that stretch of US Highway 2 is 65 mph, and the road is heavily traveled by large semis. Finally, funding issues made a build-out of the intersection unfeasible.