Gov. Ned Lamont is fine-tuning a 10-year, $18 billion transportation plan, narrowing it down to specific projects in a compromise proposal that he says will make a huge difference, saving as much as 20 minutes each way on various state highways and commuter trains. The much-anticipated proposal — known as CT 2030 — is expected in the coming weeks, but various aspects have dribbled out in recent days. Lamont wants to fix specific “choke points” that he says will ease the commute around the state, particularly in traffic-clogged Fairfield County. He is ditching a plan for electronic tolls at 53 locations across the state’s major highways in favor of tolls at specific bridges that are being replaced or repaired.