I-70 Metering at Eisenhower-Johnson Tunnel

This weekend is as good as any to remind folks that the EJMT performs metering on the weekends. This means, to avoid traffic standing still in the tunnel, they stop traffic before allowing it to proceed. This also means a Highway Patroller may lead the flow of traffic (with its lights) to keep traffic moving at a safe, consistent speed. The thinking being that higher, inconsistent speeds lead to more accidents (and overall more delays).

From GoI70:

CDOT holds or “meters” traffic at the tunnel when vehicle volumes exceed the capacity of the Interstate 70 corridor, primarily on busy Sunday afternoons in the winter and summer when traffic is at its peak. With only two lanes inside the tunnel and no shoulders, CDOT cannot allow traffic to backup into the tunnel to the point where crews would not be able to respond in a timely manner to a medical emergency, accident, fire, or other problem.

You may have noticed the testing of four lanes leading up to the tunnel, which are allowed to alternate going in using signals and flaggers (just like onramps on big highways like I-25 during rush hour). This way there is no true need to stop traffic entirely, but instead alternate four lanes down into two.

Starting in December, CDOT will begin testing Continuous Flow Metering (CFM) as an alternative to standard metering, minimizing the need to completely stop traffic at the EJMT and make metering flow more efficiently. Much like ramp metering—the traffic signals located at highway on-ramps—the new system will regulate the flow of traffic into the tunnel by alternating lanes of traffic. Flaggers will direct traffic into four lanes at the eastbound approach to the tunnel only by utilizing the paved shoulders. Recently installed traffic signals above the lanes will allow two lanes of traffic at a time to enter the tunnel every 4-8 seconds.

CDOT has posted a video simulation that compares metering versus the CFM approach and how it should help:

What have your experiences been? I saw that two weekends ago traffic was so congested there was upwards of 3 hour delays (even after dinner time). That doesn’t seem ideal…

Remember: you can check conditions yourself by visiting m.cotrip.org on your mobile web browser or by download the iOS or Google Play apps.