SEATTLE -- After days of warnings about the new lane restrictions through the construction zone that began late Thursday night, too many drivers headed out to I-5 on Friday, backing traffic up about two miles.

With phase three of the project under way, Department of Transportation crews shifted their work to the left side of the northbound lanes, leaving open only two lanes for traffic for the Friday morning commute.

Until today three lanes had been available, and the feared nightmare commute had not materialized. Traffic volumes increased each commute day since Monday as more and more drivers abandoned their alternate routes or alternate methods of transportation.

And commuters continue to be confused by the right-side collector distributor lane, which many believe is an exit-only lane. While it does allow drivers to exit off I-5, the lane continues back on to the main northbound line. (See detailed map below.)

On Friday many drivers were trying to cut into the left lane at the last minute, further slowing already heavy traffic. One even put his car into reverse and backed up into oncoming traffic to get into the left lane.

Alternate routes such as Airport Way and Highway 99 were flowing smoothly and DOT officials urged drivers to use those routes instead of I-5 through the weekend and next week.

The contractor hired to repave the road surface and replace expansion joints is ahead of schedule and the project is on track for completion by August 24th.

Since Friday night last week crews have been replacing expansion joints on a mile-long stretch of the northbound lanes between the West Seattle bridge and Interstate 90.

On a normal weekday about 126,000 drivers use the stretch of I-5 that is being repaired.

For More Information:

Check our online traffic section for continuing coverage of the I-5 construction project, get your questions answered by KOMO traffic reporter Jenni Hogan, and check travel times, live cameras and more:

http://www.komotv.com/traffic