Ganga Rail–Road Bridge (Hindi: गंगा रेल-सड़क सेतु), is an under-construction bridge across river Ganges, connecting Digha Ghat in Patna and Pahleja Ghat in Sonepur in the Indianstate of Bihar. Upon completion in March 2015, the bridge would provide easy roadway and railway link between northern and southern parts of Bihar.first trial with one engine done on 08 August 2015 is successful. 
Presently, Rajendra Setu is the only bridge that carries railway tracks across the Ganges in the state of Bihar. It was opened in 1959.
Initially sanctioned as a rail bridge, the Ganga Rail Bridge project was converted to a rail-cum-road bridge in 2006. Total cost of the project was put at ₹13,890 million, out of which ₹8,350 million was for the rail part, and ₹5,540 million was for the road part. It was expected to be completed in five years.
When completed, the 4,556 metres (14,948 ft) bridge would be amongst the longer bridges in India. The total length of construction, including approaches, would be 20 km. It would be a K-truss bridge.
According to a media report the bridge is expected to be completed by 2017. Railways is working hard to complete Ganga Rail–Road Bridge project within the stipulated time of March 2015 to ease the huge traffic flow on the Mahatma Gandhi Setu. The work is most likely to get completed by the end of 2015 as the remaining fund of Rs 300-350 crore has been allocated in the Rail Budget 2015-16.
In 1996, survey work for the proposed bridge was initiated by the Railways at three possible sites – Digha-Sonepur, Gulzarbagh-Hajipur and Ict Ghat-Sonepur. Ram Vilas Paswan was then the Union Railway Minister and he lent his support to the Gulzarbagh-Hajipur site, as Hajipur was the constituency from which he was elected. Lalu Prasad Yadav, then Chief Minister of Bihar, lent his support to the Digha-Sonepur site. In the wake of the conflicting support of the political heavy weights, disturbances broke out at Sonepur. One person was shot dead. Many experts opined in favour of building the rail bridge adjacent to the Mahatma Gandhi Setu, the road bridge connecting Hajipur with Patna. However, political opinion prevailed and the Digha-Sonepur site was selected. Rs. 24 million was spent on the survey alone. The bridge was finally sanctioned during the term as Union Railway Minister of Nitish Kumar, present Chief Minister of Bihar. The scope of work was expanded when Lalu Prasad Yadav was the Union Railway Minister.
The Ganges divides the state of Bihar in two parts. The mighty river makes communication between the two parts a difficult task.
The first effort to bridge the gap was Rajendra Setu in 1959. The next bridge across the Ganges in Bihar was the 5,575 metres (18,291 ft) Mahatma Gandhi Setu, the longest bridge in India at the time of its commissioning in 1982. It was followed by Vikramshila Setu near Bhagalpur. The fourth bridge across the Ganges in the state is the Ganga Rail–Road Bridge.
Arrah–Chhapra Bridge across the Ganges is also under construction which will connect Arrah and Chhapra. A road bridge parallel to the existing rail and road bridge, Rajendra Setu, has also been planned.