Traffic flow on Irvine’s major roadways is about to improve. These streets already use synchronized lights to keep cars moving, but there’s a hitch. Any time you pass a freeway ramp, the synchronization stops — like a broken link in a chain.

That’s because Caltrans operates these signals, which don’t communicate with city signals.

Over the next 18 months, Caltrans will upgrade its 40 Irvine signals at ramps to the 5 and 405 freeways, and 261 and 133 toll roads.

This will give the city uninterrupted synchronization on all major streets.

How Synchronization Works

Traffic-light synchronization coordinates green lights over a series of intersections to maximize traffic flow.

Irvine synchronizes lights on 19 major streets for morning, midday and evening commutes. It favors the heaviest traffic, so lights may favor traffic in one direction at morning peak and the other direction at evening peak.