Screen grab from CDOT's live streaming video system shows eastbound traffic at a standstill at 6:15 pm Sunday stretching down the Straight Creek Grade waiting on the west side of the tunnel for traffic to clear.

CDOT stopped eastbound traffic from entering the Eisenhower-Johnson Memorial Tunnels several times Sunday night due to heavy traffic on the east side backing up into the tunnel.

The practice, called “metering,” was started late afternoon on Sunday and lasted until CDOT announced at 8:38 p.m. that it had ended. Snowy conditions added with the already high number of vehicles making the drive resulted at times in standstill conditions at the Continental Divide.

When this occurs, CDOT uses 20-minute traffic stops on the west side, which it calls “metering,” in order to prevent vehicles from standing idle inside the tunnel. This is done to maintain emergency access in the event of a fire, medical emergency or other need to crews to gain access to the tunnel.

When CDOT releases the traffic, typically it catches up to the back end of the traffic jam going back to Denver, which it notes results in no actual net increase in delay for travelers.

Photo from a CDOT traffic camera looking east outside the Eisenhower-Johnson Memorial Tunnels shows the backup headed down toward Silver Plume nearly reaching the tunnel exit at 4:30 p.m. Sunday.