First planned in 2001 and approved in 2004,[4][5] the 25-year concession agreement was signed in 2008 between the Philippine government and the project's original proponent, Universal LRT Corporation.

The 1993 Updated Traffic and Transport Management Plan proposed Line 4, spanning from Welcome Rotonda to Batasan, entirely in Quezon City, for 18.35 km (11.40 mi).

Meanwhile, Spanish firms such as Construcciones y Auxiliar de Ferrocarriles, Entrecanales y Tavora, and Cubiertas y MZOV (both later merged to form Acciona) and Halcrow also participated in the study.

A branch line, which would either be an automated guideway transit or busway, would have shuttle commuters to and from San Mateo, Rizal.

[26] However, after years of delays, SMC planned to conduct a second round of bidding in 2015, due to revised construction cost assumptions.

SMC tapped the consortium of Hyundai Rotem and EEI Corporation as the engineering, procurement and construction contractor in the same year.

[31] On April 20, 2016, 15 years after initial development began, the project broke ground, with President Benigno Aquino III leading the ceremony.

[32] The line was expected to be finished by 2019,[33] but was repeatedly pushed back because of right-of-way issues regarding the acquisition of a 33-hectare (82-acre) land for the San Jose del Monte station, depot, and the intermodal transport terminal (ITT).

[34] More than a year after the groundbreaking ceremony was held, construction on the 22.8-kilometer (14.2 mi) line officially started on August 15, 2017, and has resulted in lane closures and heavy traffic along Commonwealth Avenue and Quirino Highway, both in Quezon City.

[8][35][33] The project also includes construction of a 22-kilometer (14 mi) highway from the NLEX Bocaue Interchange, up to the proposed intermodal transport terminal (ITT) located near San Jose del Monte station.

[1] Groundbreaking for Batasan station was held on October 7, 2017,[36] while the excavation for the underground guideway at Quezon Memorial Circle is ongoing as of November 2017.

[38][39] After two years of court hearings and appeals to obtain a site, the original location of the depot in San Jose del Monte (SJDM), Bulacan was moved to Quirino Highway in Barangay Greater Lagro, Quezon City.

[41] Originally, the site in Bulacan was subject to a legal case after the property owner questioned the expropriation at the Malolos Regional Trial Court Branch 11.

Transport Assistant Secretary Goddes Hope Oliveros-Libiran stated that it would take forever to resolve the case and it will no longer be pursued.

The case in Bulacan has prompted San Miguel to conduct a scheduled partial operation of the line from North Avenue to a station in Fairview in 2021.

[42] On April 14, 2023, DOTr, SMC, and the Quezon City government broke ground for pre-construction works along West Avenue, where an elevated turnback guideway would be built.

[44] This was later deemed no longer feasible, with DoTr Project Management Service (PMS) Director Eduardo D. Mangalili citing the completion of the depot as the main factor.

[49] The line will start at San Jose del Monte located in Bulacan and will end at the North Triangle Common Station in Quezon City.

The line is mostly elevated and erected either over or along the roads covered, with underground sections between Quezon Memorial and University Avenue, and at San Jose del Monte.

[54] The trains were then brought from the Port of Manila to Commonwealth Avenue and were laid on the tracks near the Tandang Sora station from September 11 and 12.

The test was also overseen by Ramon Ang on December 1, 2023, alongside officials from Hyundai Rotem, Korail, and Rhodium 688.

[60] [61] The line will maintain an at-grade depot along Quirino Highway in Barangay Greater Lagro, Quezon City, close to the proximity of La Mesa Watershed.

The project also consists of 8 additional stations and will connect areas within Quezon City, Marikina, the eastern parts of Pasig, and Cainta, Rizal.