Four rollerbladers and a few pedestrians tried to sneak onto the empty Interstate 405 early Sunday, but despite the small distraction, construction continued smoothly, Metro officials said.

"We're on time, and we still anticipate opening by 5 a.m. Monday," said Metro spokesman Rick Jager.

About 6 a.m., the four rollerbladers tried to enter the closed freeway near the Getty Center, where construction crews were working.

The California Highway Patrol cited them, along with two pedestrians who also tried to sneak onto the freeway near the Sunset Boulevard offramp, said CHP Officer Charmaine Fajardo.

"Saturday was beautiful, but this morning people may be getting a little antsy," she said. "We just cite them and tell them why it isn't safe."

Most drivers ditched their cars on the first day of the weekend-long closure of one of the nation's most-congested highways. Dubbed Carmageddon II, the effects of the shutdown of I-405 between Highway 101 and Interstate 10 also have been minimal considering the logistics, officials said.

At the construction site, crews continued to demolish the last of two pylons of the Mulholland Bridge.

Work stopped Saturday for at least an hour when a large section of the bridge that was being demolished fell down.

But the incident didn't damage the newly constructed portion of the bridge and did not cause any delays to the overall project, Jager said.

During Carmageddon I, construction crews removed the south side of the bridge, then rebuilt it. During this weekend's 53-hour road closure, crews were expected to demolish the north side, rebuild it, and then join it to the other half.

The bridge work is part of a $1 billion project to complete a 48-mile northbound I-405 carpool lane, extending from the Orange County line to the freeway's junction with Highway 101 in Sherman Oaks.