Recurring traffic bottlenecks

"Much of recurring congestion is due to physical bottlenecks -- potentially correctible points on the highway system where traffic flow is restricted. While many of the nation's bottlenecks can only be addressed through costly major construction projects, there is a significant opportunity for the application of operational and low-cost infrastructure solutions to bring about relief at these chokepoints. This document ... describes such facility breakdowns and explores the opportunity for near-term operational and low-cost construction opportunities to correct them"--p. 1.