As the Commonwealth Avenue Bridge construction project continues, relief is on the way for some commuters, state Highway Administrator Jonathan Gulliver said during a briefing Friday morning.

Gulliver said he expects the Massachusetts Turnpike to return to full capacity at peak travel hours Monday morning with four inbound lanes and four outbound lanes.

“We have met or exceeded all of our current milestones, so we’ve been really happy with the progress to date,” he said.

When asked about the possibility of delays because of weather, Gulliver said his main concern would be a thunder and lightning storm but said light rain shouldn’t have much of an effect.


“So far, we don’t see anything that’s going to really derail us, but then again we’re going to really continue to keep a close eye on it,” he said.

There has been a 40 percent reduction in traffic volume on the turnpike this week, but, Gulliver said, travel times Thursday for drivers heading west were affected by as much as an hour.

Since the project to replace the westbound portion of the Commonwealth Avenue Bridge began on July 26, Commonwealth Avenue has been closed to traffic from St. Paul Street to St. Mary’s Street, and Green Line trains have been replaced by shuttle buses between Babcock and Blandford streets.

Gulliver said these travel restrictions will remain in place until the project’s expected end date of Aug. 11.

Sophia Eppolito can be reached at sophia.eppolito@globe.com. Follow her on Twitter @SophiaEppolito.