Although the south Seattle commute remained mild this morning, the city Department of Transportation noticed a pinch point at the north end of the First Avenue South bridge, where Highway 99 and East Marginal Way South converge. (State traffic maps showed the area as "red," meaning heavy traffic.)

The intersection became congested enough that the city increased the length of its green signals northbound, said SDOT spokesman Gregg Hirakawa.

"This project still has many more days to go. People should not be complacent, thinking traffic is not a problem," he said. If everyone jumps back into a car, backups will occur, he said.

Two lanes of Interstate 5 remain closed as contractors resurface the northbound pavement near Spokane Street. A third lane could close as early as Thursday, if the construction continues to run ahead of schedule, state transportation officials have said.

So far, thousands of people have prevented gridlock by staying home from work, using transit, or taking different routes.

by Mike Lindblom