Notice of road closures, A421 and A4421

What we are doing

Throughout the summer, we have been carrying out works for the main construction of permanent realignments and overbridges for the A421 (near Finmere) and A4421 (near Newton Purcell). These new bridges will carry traffic over the HS2 railway and along the newly aligned road network.

We will be carrying out utility surveys to facilitate our final utility diversions for both of these roads. To carry out these surveys safely, we will need to close a section of the A421 and A4421 with a signed diversion. These closures are required because our teams will be working directly in the carriageway.

Following these surveys, the final utility diversions will be carried out. Majority of these works will take place under full 24-hour weekend closures or night time road closures. The final tie-in works to knit in the new road alignments to the current road network work are expected to take place in spring 2025.

When will these works take place?
To reduce our impact on the local area, the A421 and the A4421 will not be closed at the same time. We have coordinated our works so that closures will alternate between the two roads.

The tables found in the linked document outlines the expected closure dates for the A421 and A4421. The closures and appropriate diversions will be signposted in advance.

Where possible, we will keep the road open and reduce full road closures to temporary traffic lights. Signage on the road will indicate the change. Should our teams complete the works ahead of schedule we will work to reopen the roads as soon as possible.

Download information relating to these works

• Notice of road closures, A421 and A4421

Find out more about

• Buckinghamshire and Oxfordshire

If you have a question about HS2 or our works, please contact our HS2 Helpdesk team on 08081 434 434 or email [email protected]