Station Approach in Hayes will be closed in one direction until tomorrow (March 18) due to a burst water main.
Emergency repairs have been taking place between Bourne Way and Pickhurst Lane.
Six bus routes - 119, 138, 246, 314, 353 and 638 - are on diversion with delays possible.
A spokeswoman for Thames Water said: "Our engineers have been working in Station Approach to fix two leaks on a water pipe.
"The pipes are now repaired, and we’re focusing on getting the road back to normal.
"We hope to reopen the road by tomorrow lunchtime."
Have you seen the burst water main? Do you have any photos? E-mail the newsdesk or call 01689 885 711.