Roads in the south-east are expected to be among the busiest in the country over the Easter break and today is likely to be the busiest day of the holiday.
The A303 westbound through Hampshire, Wiltshire and Somerset and the M25 around Heathrow Airport are expected to have the heaviest traffic, according to Trafficmaster.
Highways England says that more than 550 miles of roadworks will be lifted to help ease congestion.
A large number of rail engineering works will be taking place over the weekend, which will also affect journey times.
There will be no Southeastern services to or from the London stations of Charing Cross, Waterloo East or Cannon Street.
Train passengers in the Thames Valley face disruption from 11.55pm on Thursday (April 2) until 3.30am on Monday (April 13) while the final stage of Reading's rail update is completed. Work takes place on the track between the town and Didcot.
Services in Kent will also be suspended.
Gatwick Airport is expecting 11% more passengers than last Easter - a total of 480,000 people. Nearly 400,000 are leaving from Heathrow airport over the weekend.