Traffic on the A303 around Stonehenge is expected to be very busy on Saturday, 20 June and the morning of Sunday, 21 June during the summer solstice celebrations.
Up to 40,000 people are expected to attend the celebrations which take place at sunrise on Sunday.
Stonehenge will be open for the celebrations between 7pm on Saturday, 20 June to 8am on Sunday 21 June.
People attending the event are being encouraged to use public transport, including a frequent special bus service running from Salisbury to avoid delays reaching Stonehenge.
Road users travelling by Stonehenge on the A303 are advised to plan their journeys in advance and allow longer to reach their destinations.
Trains run regularly to Salisbury from London, Bristol, Bath and Southampton.
The local Wilts and Dorset Bus Company, Salisbury Reds, will be running a special service from Salisbury railway station and from Stand U in New Canal, to a drop-off point near Stonehenge. The buses will also stop at any recognised bus stop along the line of the route, which is via Amesbury.
Details on train and bus timetables and fares are available as follows:
Bus service information
Telephone: 0845 6000 650
Telephone: 0345 7000 125
Telephone: 08457 48 49 50
Members of the public should contact the Highways Agency Information Line on 0300 123 5000.
Journalists should contact the Highways Agency press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.