Our roads are killing wildlife. The new infrastructure law aims to help

Just outside of Los Angeles, in one of the most human-modified parts of the planet, a rare coastal ecosystem is being pinched against the Pacific Coast. The mountain range is home to one of the highest concentrations of threatened and endangered species in the country.

And some are suffocating.

For the better part of the last century, the Santa Monica Mountains have been effectively cut off from the larger world, hemmed in by seawater and sprawl. Highway 101, carved across the range's northern foothills, "has become this impenetrable wall for wildlife," said Beth Pratt, California regional executive director for the National Wildlife Federation. "And both plants and animals need movement to be resilient and survive."

This spring, Southern California