Opponents Want Legislature to Halt Construction

"If they're serious about fighting climate change, they need to study the impacts of this highway and, if necessary, they need to pull the plug until they do that," Smith said.

The connector, the first major highway construction project in the Washington area in a generation, would link the Interstate 270 corridor in Montgomery County and the Interstate 95/Route 1 corridor in Prince George's County.

Supporters say it is vital to the state's economy because it will connect high-growth centers and make local east-west roads beyond the Capital Beltway safer and less congested.

Opponents say the highway will cause too much environmental damage, pose serious health risks and increase pollution by encouraging more driving.

State Highway Administrator Neil J. Pedersen said delaying construction would cost the state $100 million to $200 million in contractor fees. He said the state has studied environmental and health impacts of the highway by following federal requirements and using the best scientific methodology available.

Staff researcher Karl Evanzz contributed to this report.