In Berkshire, the M4 eastbound has 3 lanes closed due to a serious collision between J6 and J5.
Traffic is passing the incident by using the hard shoulder as a running lane.
Long delays of over 1 hour are now being measured on the approach to the incident between Reading and Slough.
Road users are advised to allow plenty of extra journey time or to use and alternative route, if possible.
Thames Valley Police is currently on scene at a serious road traffic collision on the M4 between junction 6 and junction 5
Lanes 2 and 3 are currently closed just before junction 5 and will be for several hours. Drivers are advised to avoid the area if possible.