Drivers are set for more than a year of delays as two major roadworks along Black Country motorways get under way this week.

A speed limit of 50 mph will be in force on various stretches of the M6 between junctions 8 and 10a while a £150 million jam-busting scheme to open up the hard shoulder takes place. And 15 weeks of work on the M5 Oldbury viaduct starts today, with Stone Street, between Lodge Street and Trinity Street being closed at various times until November.

It will be shut from 7pm until the morning of September 16, then closed again from October 2 to 17 and November 2 to 17

Narrow lanes will also be put in place ahead of work on the M6, preparation for which took place over four nights last week when cats’ eyes were ripped from carriageways.

Restrictions will start between Junction 10, for Walsall and Wolverhampton, and Junction 10a for Essington until March 2010.

The hold-ups will then move to Junction 8 at Wednesbury, where the M6 meets the M5, and 10 between March and November next year.

It is hoped the project will be completed by spring 2011 after which drivers will be directed to use the hard shoulder during peak congestion by electronic signs above each lane.

Highways Agency spokesman Anthony Aston said today: “We started traffic management preparation work on Thursday which involves things such as taking the cat’s eyes off the road and taking the white lines off and putting new narrower lanes on.

“It will also involve putting a temporary safety barrier in.

“The main work will start towards the end of this week and the speed limit will come into force after the preparation works.”

The work on the M5 will see beams repainted and scaffolding will go up around the viaduct.

One lane on Stone Street will be closed for two months.

Nathan Wallis of the Highways Agency said the 15 weeks of work was “preventative maintenance” to stop the viaduct falling into disrepair.

He said:”This will not affect motorway traffic but will mean diversions for drivers on local roads.” Traffic will be diverted.