Measures to Alleviate Congestion at Rural Intersections – Case Study: SH-55/Banks-Lowman Hwy Intersection Grant uri icon



  • Many state highways experience a surge in traffic flow levels on certain “high-travel” days on the year such as Memorial Day weekend, thanksgiving holiday, as well as other major seasonal travel activities. This causes excessive delay to vehicles on the minor approach attempting to turn left to the major highway due to the platooned nature of the high volume traffic traveling on the highway. If the minor approach is also experiencing high levels of traffic demand, vehicles will experience significant congestion and a deteriorated level of service. A typical example of such congestion is at the SH-55/Banks-Lowman Hwy Intersection. During holiday weekends, ITD controls the intersection by flagging operations to allow Banks-Lowman traffic an opportunity to get onto the highway. Without flagger control, there is insufficient available gap side street traffic to enter the highway and traffic backs up for miles resulting in long delays that can lead to motorists’ impatience taking shorter gaps to enter the highway causing safety concerns and potential crashes. During non-holiday summer weekends, recreational traffic has increased to the point where insufficient available gaps is causing extensive side street delays as well as very long queues on Idaho 55.

date/time interval

  • January 1, 2014 -