The road was closed between the junction with Stainland Road and the junction signposted Lowfields Business Park while Northern Gas Networks carried out emergency gas works to repair the damage.
The Calderdale Way between Halifax and Huddersfield was closed all day on Wednesday causing major delays on surrounding routes.
Throughout the day traffic was diverted via Stainland Road, Rochdale Road, Saddleworth Road (B6114), Briggate/Huddersfield Road and Elland Riorges Link (or by this route reversed).
Engineers are working hard on the repairs, with a contraflow system on the road due to be in place today (Thursday).
Calderdale Council confirmed that lane restrictions are being put in place on Elland bypass while Northern Gas Networks repair the gas main.
The Councils said the road is scheduled to fully open by evening time.
The damage to the gas main was caused late on Tuesday by a third party contractor carrying out work in the area.
Neil Travers, Operations Manager for Northern Gas Networks, said: “We’d like to apologise for any inconvenience road users may encounter and thank them for their patience as we work to complete this emergency gas work as safely and quickly as possible.”
Anyone that smells gas or suspects carbon monoxide should call the National Gas Emergency Service immediately on 0800 111 999. This line is in operation 24-hours a day, seven days a week.