The A43 will be closed to through traffic between Brackley and Towcester from 5am to 9pm from Friday until Sunday. Non-race traffic is advised to avoid the area if at all possible.
Around 315,000 people are expected to converge on Silverstone over the three days.
Highways England emergency planning officer Steve Parker said: “While Highways England does all we can to alleviate congestion and keep the traffic flowing, obviously it will be busier than normal in this area.”
Motorists heading elsewhere should plan ahead and leave extra time for their journeys.
Highways England will use its electronic message signs on approaching motorways to give drivers information about any diversions and delays, and provide up-to-the minute traffic information using local radio.
Northamptonshire Police have been reminding motorists attending the Grand Prix that they must park at their campsite of choice, or in accordance with Silverstone Circuit’s parking instructions.
All parking restrictions within local villages, and on the main routes in and around the circuit, must be observed, said Supt Mick Stamper, who is leading the policing over the weekend.
He added: "Northamptonshire Police will do everything we can to make sure everyone coming to the British Grand Prix has an enjoyable and safe weekend.
“Improvements to the road network around Silverstone have reduced delays to a minimum. However, motorists should still allow additional time for journeys to and from both Silverstone and the neighbouring area during the Grand Prix weekend.
“I would urge all those driving to the events to pay particular attention to direction signs on the major roads.”
Further information including travel updates can be found at: