Delhi–Alwar Regional Rapid Transit System (Delhi–Alwar RRTS) is a 164 km long under-construction[2][3] semi-high speed rail corridor connecting Delhi, Gurgaon, Rewari and Alwar.

[6] The National Capital Region Planning Board (NCRPB) as part of its Integrated Transportation Plan 2032 identified eight rail based rapid transit corridors to improve the efficacy of transportation system in the NCR.

The Urban Mass Transit Company was given the job of conducting a feasibility study on 23 March 2010.

The contract was then transferred to NCRTC on 18 January 2017 to carry the study forward.

[1] On 15 June 2018, the 100 km long first phase of the project from Hazrat Nizamuddin to Shahjahanpur-Neemrana-Behror, at an estimated cost of ₹25,000 crore, was approved by the Haryana government.