Motorists heading towards next week's York Ebor race meeting will find themselves taking new routes. A new traffic plan is being put into practice in preparation for next year's Royal Ascot at York.
Drivers arriving for race meetings currently follow a route that has not changed for 60 years, which causes congestion in residential areas.
A crowd of 32,000 is expected for the Ebor meeting and council officials will carry out an evaluation of the trial.
Councillor Bill Woolley said residents' views would be taken into account in the council evaluation.
"We hope that the new plan will help minimise congestion, particularly for those who live and work in the area surrounding the course, and make it easier for people to enter and leave the racecourse," said Mr Woolley.