After a series of public hearings, the East–West Gateway Council of Governments adopted light rail as the region's preferred mode.

[4]: 201  The city of St. Louis acquired unused railroad facilities and property with an estimated value of $100 million and donated it to the project, supplying the local match.

Entering St. Louis City at Skinker Boulevard, the line stops at the Delmar Loop station and its namesake entertainment district.

The Red Line continues south through Belleville, Illinois, to its terminus at the Shiloh–Scott station near Scott Air Force Base.

The bridge pier style is a signature of MetroLink design and appears in the subsequent St. Clair and Cross County extensions.

Titled St. Louis Rhythm and created by Richard Elliot, it was made using roadway reflectors on 16 concrete Jersey barriers that are activated by the headlights of passing cars.

Titled Blue Train and created by Clark Wiegman, a cubist locomotive represents the opening eight bars of the melody of “St.

At night, it becomes a geometric abstraction about linear dynamism and the implied form of the bridge punching through the surrounding ambient light.

[34] In 2019, the St. Clair County Transit District was awarded $96 million in Illinois infrastructure funding to build a 5.2-mile (8.4 km) extension of the Red Line from Shiloh-Scott to MidAmerica St. Louis Airport in Mascoutah.

[43][44] Elsewhere, catenary wire, curve tracks, platforms, retaining walls, staircases, and system conduit are to be upgraded or replaced.

[45][46] In 2026, Metro expects to complete upgrades to the Supervisory Control Automated Data Acquisition (SCADA) and Public Address/Customer Information (PA/CIS) systems.