LOS ANGELES (KTLA) -- 'Carmageddon II' came to an end ahead of schedule, with all lanes of the 405 Freeway through the Sepulveda Pass re-opened to traffic by midnight Sunday.

The two-day closure of the 10-mile stretch of the 405 was part of a $1-billion, four-year project to expand the notoriously congested freeway with a northbound carpool lane.

Crews were required to finish their work by a deadline of 5 a.m. on Monday morning, but they wrapped up with time to spare.

By early afternoon Sunday, the last pieces of the Mulholland Bridge had been removed.

Crews began hauling away 2,700 cubic yards of material, including 300 tons of steel, and a four-foot-thick pad of dirt dumped on the roadway to protect it from falling debris.

By nightfall, street sweepers were scouring the roadbed, and inspectors were looking for damage before giving final clearance for reopening.

Workers began removing barriers to the northbound 405 on-ramps between the 10 and 101 freeways around 8:30 p.m. Sunday, and the southbound lanes followed.

Los Angeles Mayor Antonio Villaraigosa declared the weekend "a resounding success," speaking at a press conference at "Camp Carmageddon" overlooking the freeway.

"People understood they needed to stay away from the area," Villaraigosa said. "They did what they needed to do to make sure it went as smoothly as it did."

Unlike last year's freeway closure, which finished 17 hours ahead of schedule, this time construction crews used most of their time to make as many improvements to the 405 as possible, officials said.

Work crews also contended with a considerably bigger job this time around.

The northern side of the Mulholland Bridge over the 405 that was demolished this weekend was longer than the southern side knocked down last year.

Crews had to demolish four concrete support structures -- two more than last year -- each encased with 3/4-inch steel to protect against earthquakes.

In addition, the demolition proceeded more cautiously than last time to ensure that raining chunks of concrete and steel didn't damage the new bridge under construction.

"We knew it was going to take longer because there was 30% more bridge to demo," said Mike Barbour, director of the 405 widening project for the Metropolitan Transportation Authority.

"We didn't care as much about getting it done ahead of schedule. We thought it was more important to finish as much work as we can this weekend to save future closures."

To that end, transportation officials deployed extra crews along the Sepulveda Pass to fill potholes, trim trees and pave three southbound lanes.

By packing weeks of work into two days, the city saved an estimated $150,000, according to Villaraigosa.

For the most part, the work of Carmageddon II went smoothly, officials said.