Full-fledged traffic movement commenced on Rajendra Setu over the Ganga at Mokama from Sunday, which will ease the load on the dilapidated Mahatma Gandhi Setu.

The 2-km-long rail-cum-road bridge around 100km east of Patna was under repair since December 1, 2014, and only one way traffic was allowed. Heavy vehicles, which were prohibited under the one-way system during the repair work, are now allowed entry.

As heavy vehicles are restricted on the Gandhi Setu as well, most trucks had to travel another 225km east of Patna to Bhagalpur to cross the river via the Vikramshila bridge.

The repair was initially scheduled to be completed by June 15 but was delayed.

A senior official in the road construction department said: "The repair work got delayed owing to several reasons, including an inquiry by the CBI and short supply of sand."

East Central Railway (ECR) chief public relations officer Arvind Kumar Rajak said Calcutta firm Rawatsons Engineers was tasked with the repair. "The firm completed the works with a slight delay and vehicular movement started today," he said.

Patna district magistrate Sanjay Kumar Agrawal told The Telegraph on Sunday: "We received a letter from the ECR on Saturday that the repair work on Rajendra Setu has been completed. We started vehicular movement on the bridge from this morning. It would reduce vehicular load on Gandhi Setu."

The bridge was inaugurated by the first President of India, Dr Rajendra Prasad, in 1957. The train track is on the lower deck, the road is on the upper deck. Senior officials in the ECR's Danapur division said the steel structure underneath the road deck was severely damaged and it was retrofitted after ripping off the concrete road base. The bridge was the only lifeline connecting south and north Bihar till 1982, when Gandhi Setu was opened. Even today, commuters use the Rajendra Setu to travel from Patna to places such as Begusarai and Khagaria. Many trains also use the bridge.

Commuters and transporters heaved a sigh of relief with the start of vehicular traffic. "Trucks coming from across the country headed to eastern and northern parts of the country were seen moving at a snail's pace near Patna owing to restriction on heavy vehicles on Gandhi Setu and repair on Rajendra Setu," said Sanjeev Sinha, who is part of the faculty at the National Institute of Technology-Patna, and a traffic expert.

"It took two-three days to cross the Ganga for going from north to south Bihar and vice-versa. The situation would now ease considerably."

The Union ministry of road, transport and highways is likely to rope in a firm for overhaul of Gandhi Setu by August 5. The Union cabinet on June 22 approved rehabilitation of the Setu at an estimated cost of Rs 1,742.01 crore.

The firm for the Setu's repair was initially scheduled to be selected by July 15 but the ministry has extended the bidding deadline to August 5.

Work is also on at the Bakhtiyarpur-Tajpur bridge around 45km east of Patna. Chief minister Nitish Kumar laid the foundation stone for the 5.575km bridge in June 2011 and it was initially scheduled to be completed by the end of 2015; the new deadline is January 2018.