ZEPHYR COVE, Nev. — While Cave Rock tunnel construction began Monday, officials say road work will not impact next week’s Amgen Tour of California, a cycling race heading around Lake Tahoe on Thursday, May 19.

The project includes a 60-foot tunnel extension on the north side of westbound tunnel lanes, plus bike safety and stormwater management updates.

“Nevada Department of Transportation has been coordinating with representatives from the Amgen Tour of California women’s race and the Lake Tahoe Visitors Authority since last November,” said NDOT’s Devin Cartwright by email. “The race is led and followed by Nevada Highway Patrol and California Highway Patrol officers, who will provide a rolling roadblock for racers and race support vehicles as they travel around Lake Tahoe.

“As racers approach Cave Rock, law enforcement officers in the lead will stop traffic on both sides of the tunnels. Flaggers will be on site to provide assistance as necessary,” Cartwright continued. “Racers will proceed safely through the work zone in the eastbound tunnel without any surrounding vehicular traffic and then continue around the lake. The whole process should take about 20 minutes from the time traffic is stopped to when the motorcade is fully beyond the work zone.

“This is the same delay that’s expected as a result of the race motorcade all around the lake.”

According to NDOT, the tunnel expansion project is meant “to enhance traveler safety and roadside water quality on U.S. 50 in the Cave Rock area. … During construction, traffic will be reduced to one lane in each direction through the eastbound Cave Rock tunnel, with reduced speed limits and some limited travel delays to be expected. Oversized and over-dimensional semi-trucks will not be permitted through the tunnel during construction. Periodic, short-term lane closures will also take place on U.S. 50 north of Cave Rock.”

The approximately $6 million project by contractor Q&D Construction will continue through fall of 2016, officials said.

Tunnel work this summer is the result of loosened boulders falling on the highway, causing safety concerns for vehicles, pedestrians and cyclists. NDOT installed temporary netting after boulders fell on the roadway during the winter of 2014-15 to mitigate rockfall until the tunnel extension was built.

“Making sure that drivers get safely where they need to go is our top priority,” NDOT district engineer Thor Dyson said in a news release. “This project is just one of many ways we are enhancing travel and preserving motorist safety in the Tahoe area.”

Motorists can expect up to 20-minute delays on the East Shore through the project’s duration.