Police reopened all westbound lanes of the H-1 freeway near the Aiea Heights overpass after a cement or soil spill brought traffic to a crawl for thousands of motorists Saturday.

Police had closed off all but the far left westbound lane of the freeway near the Kaamilo Street after a truck spilled some kind of mixture in three lanes of the highway, a dispatch supervisor said. 

Police said the spill occurred around 2:50 p.m. Saturday.

The lanes were reopened at 7 p.m., but traffic was backed up for miles.

Dispatch reported that the spill was some kind of asphalt or concrete mixture but a traffic alert described it as soil. 

A Honolulu Fire Department spokesman said the spill was bigger than officials initially thought. As of 3:30 p.m. four engine companies, a ladder truck, a tanker and a battalion chief have been called to the scene.