Expo Line test train on the bridge over Venice Boulevard before heading back west. Photos by Steve Hymon/Metro.

The train heading west from Culver City with downtown Los Angeles in the distance.

The train halts before crossing Bagley Avenue.

Work crews huddle up before the test runs begins Monday morning.

The train after it had been towed overnight to Bagley Avenue crossing. The test, however, came with the train under its own power.

The test train early Monday after being towed to Bagley Avenue crossing. Photo by Jeff Zucker/Expo Line Construction Authority.

Crossing Bagley Avenue under its own power. Photo by Jeff Zucker/Expo Line Construction Authority.

Crossing under the Santa Monica Freeway. Photo by Jeff Zucker/Expo Line Construction Authority.

Photo by Jeff Zucker/Expo Line Construction Authority.

Measuring clearances. Photo by Jeff Zucker/Expo Line Construction Authority.

Some of the work crews for the clearance testing. Photo by Jeff Zucker/Expo Line Construction Authority.

As expected, clearance testing for the second phase of the Expo Line light rail project began this morning with a train running under its own power running west from Culver City. This is the first time a Metro Rail light rail vehicle has crossed the new bridge over Venice Boulevard.

Clearance testing is exactly as it sounds: the idea is to ensure that train cars run clear of all structures along the tracks, including platforms, signals and other items. It’s done at very slow speed with workers walking along the train to monitor proper spacing. Testing will continue throughout the month — please be aware of trains at all rail crossings!

I’ll add more photos later. The second phase of the Expo Line is expected to open next spring between Culver City and downtown Santa Monica, allowing rides between 7th/Metro Center in downtown Los Angeles and downtown SaMo. The project is funded by Measure R, the half-cent sales tax increase approved by Los Angeles County voters in 2008. The project is being built the Expo Metro Line Construction Authority, an independent agency. When construction is complete later this year, the Authority will hand over the project to Metro, which will operate the line.

Here’s a map showing what the Expo Line will look like when complete: