TEMPORARY traffic lights are in use as repairs are carried out on a stretch of busy Leeds Road at Deighton.
Crash barriers on the railway bridge are being upgraded to improve safety and the bridge is being re-waterproofed.
The temporary lights are expected to remain in place until September.
A Kirklees Council spokeswoman said: "We apologise for the inevitable disruption that this will cause."
The work has been scheduled to follow the replacement of water, gas and electricity services and the construction of the new Trident Business Park.
Highways engineers said the bridge work was being done now because roads were quieter during the school holidays.
For the first time, the council has included a clause giving contractors Balfour Beatty a financial incentive to complete the work quickly.
Some of the work will be carried out during evenings and weekends to speed up the project.
