Two babies born in their parents' vehicles on Interstate 5 near Seattle this week have raised the area's highway birth count to four for the month.

The most recent birth was Tuesday morning, when Alexa Rodriguez decided she'd had enough of the gridlock and made her appearance in parents Magin Rodriguez and Wendy Neba's 4Runner.

Monday, a similar birth took parents Liz and Brian Kirkman by surprise on I-5, the Seattle Post-Intelligencer reported.

Both couples were on their way to hospitals for the deliveries but were caught in heavy traffic, State Trooper Jeff Merrill said. Both female babies and their mothers were in good condition Wednesday, the newspaper said.

Merrill said elsewhere in the Puget Sound area, two troopers delivered a child in a restaurant parking lot last week in Pierce County, and on Jan. 5, a baby boy arrived while his parents were stuck in traffic headed for the hospital -- again on I-5, Merrill said.