Interstate 170 (Missouri)

Interstate 170 (Missouri) is a short auxiliary Interstate spur in St. Louis County serving the inner suburbs of St. Louis. The route connects portions of I-64, US 40, and I-270 with local arterials and shopping districts near Brentwood and Richmond Heights. Originally planned as part of a more extensive network, it remains one of the shorter three-digit Interstates in the Interstate Highway System.

Route description

I-170 begins at a junction with I-64/US 40 near the intersection of Hanley Road and Skinker Boulevard, immediately adjacent to Forest Park, Washington University, Saint Louis University facilities, and commercial areas serving Clayton and University City. The freeway proceeds north through suburbs including Richmond Heights, passing near the Saint Louis Galleria and interchanges for Ladue Road and Olive Boulevard, providing access toward Creve Coeur and Chesterfield. Continuing, I-170 crosses I-64 feeder roads and carries traffic north toward Brentwood and Maplewood, terminating at a three-way junction with I-270 and local roads that link to Kirkwood and industrial zones near Lambert–St. Louis International Airport. Along its alignment the highway parallels historic corridors used by Missouri Pacific Railroad and connects to several arterial routes that lead to cultural sites such as the Gateway Arch and transportation hubs like the MetroLink system.

History

The corridor that became I-170 was proposed during the mid‑20th century planning efforts led by regional agencies including the Metropolitan St. Louis Sewer District era planners and state engineers from the Missouri Department of Transportation. Initial plans in the 1950s and 1960s envisioned a more extensive north–south freeway linking Downtown St. Louis with suburban ring roads such as I-255 and I-270, influenced by federal policies of the Federal-Aid Highway Act of 1956 and regional growth driven by corporations headquartered in Clayton and industrial employers such as Anheuser‑Busch and McDonnell Douglas. Community opposition in neighborhoods like University City and Richmond Heights—alongside funding reallocations during the administrations of state governors such as Warren E. Hearnes—led to truncation of the scheme, resulting in the present short spur completed in phases between the late 1960s and 1970s. Over the decades the highway underwent resurfacing and interchange reconstruction projects coordinated with agencies including the Federal Highway Administration and saw modifications tied to redevelopment initiatives near the Saint Louis Galleria and the Brentwood Promenade.

Exit list

The exit sequence on I-170 serves major local and regional destinations: - Southern terminus: junction with I-64/US 40 — access to Clayton, Forest Park, Washington University. - Exits for Ladue Road — access to Creve Coeur and Maryland Heights commercial corridors. - Exits for Olive Boulevard — access to Richmond Heights retail and Saint Louis Galleria. - Northern terminus: interchange with I-270 — connections toward Missouri River crossings, Lambert–St. Louis International Airport, and northwestern suburbs including Bridgeton and Chesterfield.

Future and proposals

Periodic proposals for extension or conversion have surfaced in planning documents from the Bi-State Development Agency and East–West Gateway Council of Governments, including ideas to extend the spur south into Downtown St. Louis or to convert portions to a boulevard to support transit integration with MetroLink and bus rapid transit projects championed by regional officials and urban planners influenced by precedents from cities like Portland and Minneapolis. Environmental reviews under the National Environmental Policy Act and funding constraints overseen by the Federal Highway Administration and Missouri Department of Transportation have so far kept major changes from proceeding. Local redevelopment efforts around corridors near the Saint Louis Galleria and Brentwood Promenade continue to generate traffic studies by consultants and interest from stakeholders including municipal governments of Clayton and Brentwood.

See also

- Interstate Highway System - Interstate 270 (Missouri) - Interstate 64 (Missouri) - U.S. Route 40 in Missouri - St. Louis County, Missouri - Gateway Arch National Park - MetroLink (St. Louis)

Category:Interstate Highways in Missouri Category:Transportation in St. Louis County, Missouri