The I-70 Mountain Express Lanes (MEXL) are interstate shoulders used as a temporary congestion relief solution for 13-miles of eastbound and westbound I-70 between Idaho Springs and Empire in Clear Creek County. These shoulder lanes are operational only during peak travel times, and they are a part of Colorado’s Express Lane system managed by the Colorado Transportation Investment Office (CTIO).
The MEXLs are unique because they are a temporary improvement built into the existing shoulder of I-70 to “buy time” and provide congestion relief during high volume travel times until a long-term solution is implemented. Because they are built into existing shoulders, the lanes are narrow and can pose safety and operational concerns. The Federal Highway Administration (FHWA) approved the implementation of the MEXLs with the expectation that the operations would be closely managed and limited to peak congestion periods only.
When the I-70 MEXL lanes are open, there is no emergency shoulder of any kind for the 13-mile stretch of interstate, which limits law enforcement safety and capability to respond to an incident. Therefore, the FHWA set the maximum number of operational days for the eastbound I-70 MEXL at 100 days and the westbound I-70 MEXL at 125 days. CTIO analyzes historic traffic volumes and patterns to determine the days and hours of operations. When an incident occurs on I-70, the MEXL lanes may be opened with tolls waived as needed to mitigate impacts of a crash. Opening the lane for an emergency response is not counted against the number of allowable operational days.
Learn more about the I-70 Mountain Express Lanes here.