A council has called for a bridge to be built to link two villages which could be cut off from each other by the planned HS2 rail line.
The proposed spur linking the railway with the West Coast Main Line would cut across Wigshaw Lane, the road between Croft and Culcheth, near Warrington.
Warrington Council leader Terry O'Neill said the plan would close a "vital route" and create long diversions.
An HS2 spokesman said the project was "looking at alternatives".
In a letter to the transport secretary, Mr O'Neill said the road was used by 500 vehicles every hour during busy periods, as well as cyclists and pedestrians.
"Under the current proposals, a significant diversion... would be needed for everyday trips", he said, adding that a detour would "add significantly to many thousands of car journeys".
"This council urges you to direct Wigshaw Lane is not closed and a bridge connection is provided over the route."
Croft resident Siobhan Carr said villagers used Culcheth for most amenities and a diversion would mean "five minutes will become twenty minutes in the car, probably more when you add in the congestion".
However, 19-year-old Tobias Oxley, who lives in Culcheth, said HS2 was "a great idea" that would "provide loads of employment opportunities for young people".
The HS2 spokesman said those involved in the project "recognise people's concerns about Wigshaw Lane and are looking at alternatives".
"We encourage everyone to have their say in our public consultation, so that we can design and build the best possible railway," he added.