Slip roads – construction of two new slip roads on the M25 (between junction 16 and 17) for the sole use of HS2 construction traffic are now complete.
Tunnels – construction of two tunnels being built underneath the M25. The tunnels which cross the M25 between junction 16 and 17 are the beginning of a 16km tunnel which is to run through the Chiltern Hills.
These works are being carried out by HS2. For more information you can find contact details on the HS2 website.