Interstate 670 Kansas / Missouri

Overview

Designated the Jay B. Dillingham Freeway, Interstate 670 is a short urban connector linking I-70 in Kansas City, Kansas with I-70 and U.S. 71 at the southeast corner of Downtown Kansas City, Missouri. I-670 provides a direct route for through traffic along I-70 as the parent route loops north around the Central Business District.

The Dillingham Freeway travels along a viaduct from the Kansas River bridge and I-70 east to I-35 and the Alphabet Loop. The Alphabet Loop is the nickname given to the belt route encircling Downtown Kansas City along the combination of I-35, I-70, U.S. 71 and I-670. All off-ramps along the loop are numbered as Exit 2 with lettered suffixes from A to Z. Interstate 670 makes up the south leg of the loop as it passes below Kansas City Convention Center through a pair of tunnels to the immediate east of I-35. The remainder of I-670 travels below grade with a 45 mile per hour speed limit to Interstate 70, U.S. 24/40 and U.S. 71 by the Paseo West community.

Mileage by State

Kansas	1.64 mi
Missouri	1.17 mi

Data Sources

December 31, 2021 Interstate Route Log and Finders List

History

Interstate 670 was approved by the American Association of State Highway Officials (AASHO) between Kansas City, Kansas and Kansas City, Missouri on June 30, 1970. The Missouri Highway Commission plan to build an eight tenths of a mile section of six lane elevated highway was approved by the U.S. Department of Transportation on December 27, 1971. The project cost $12.5 million and was 90 percent federally funded.¹

I-670 was extended east over the south leg of the Alphabet Loop when Interstate 35 was relocated to run along the north and west legs of the Downtown belt route. Missouri applied to the American Association of State Highway officials (AASHTO) for these route changes on November 15, 1975. Action on I-670 was deferred at that time while the I-35 relocation was approved on November 12, 1976.

Interstate 670 in Kansas City was fully opened to traffic in January 1990 as the final route of the original Kansas Interstate Highway System to be completed. The viaduct that carries the Kansas section of I-670 cost $75 million of the overall $130 million price tag to build I-670.^2,3 Completion of the elevated roadway garnered the grand award by the Consulting Engineers Council of Missouri in March 1991.⁴

Approved by voters in 1973, the Kansas City Convention Center was located wholly north of Interstate 670 between Broadway and Wyandotte Street in southwest Downtown when it opened in 1976. A major expansion project for the complex broke ground on October 24, 1991 to more than double the size of the Bartle Hall exhibit space.⁵ Supported by four 260 foot pylons, the new Bartle Hall was constructed above Interstate 670 between Broadway and Central Street. The $144.4 million facility was formally opened by the city during a ribbon cutting ceremony held on September 24, 1994.⁶ A second lid over Interstate 670 would be added later.

Kicking off with a ceremonial groundbreaking on June 17, 2005, further expansion of the Kansas City Convention Center complex added the Grand Ballroom over I-670 between Central and Wyandotte Streets. The initial budget of $145.1 million included $7.6 million in state funds to both demolish the closed westbound on-ramp from Wyandotte Street and remove the Central Avenue overpass above I-670.⁷ The ballroom opened on April 28, 2007.

Another project underway by 2005, four blocks to the east of the Grand Ballroom, involved construction of a new concert and indoor sports arena. The project resulted in the permanent closure of the McGee Street westbound off-ramp on January 4, 2006.⁸ $26 million in road work along I-670, from summer to October 2007, included the addition of a new westbound off-ramp to replace the McGee Street exit further east at Locust Street and Truman Road.⁸

East End  ‐ Kansas City, KS

East at

Interstate 670 emerges from below the Grand Ballroom of the Kansas City Convention Center and expands to three eastbound lanes at the Baltimore Avenue overpass. The freeway travels below grade between the Central Business District and Crossroads communities to Exits 2 N/2 M with I-70/U.S. 24-40 and U.S. 71. 10/07/21

West at

Turning north by the Washington-Wheatley neighborhood, the first sign for Left Exit 2 L / I-670 (Dillingham Freeway) on I-70 west appears at Exit 4 B / 23rd Street). 05/07/22

East South at

I-70/U.S. 24-40 turn south from I-29/35 to overlap with U.S. 71 for 0.35 miles to Interstate 670 / Exit 2 L. 10/07/21

North at

Leading north from Hospital Hill, U.S. 71 (Bruce R. Watkins Drive) passes over 19th and 18th Streets leading into the exchange with Interstate 70, I-670 west and U.S. 24/40. 11/03/16

East End – Past Views

Past Views Gallery (Tap to Expand / Collapse Section)

at

Four lanes of I-70/U.S. 40 continued west to the directional interchange (Exit 2L) with I-670 and U.S. 71 (Midtown South Freeway). Sign changes made here replaced the I-670 sign to include a left exit tab. 10/17/04

West End  ‐ Kansas City, KS

West at

Exit 1A for Central Avenue provides access from westbound I-670 to I-70/U.S. 24-40 east and U.S. 169 north toward Downtown, in addition to U.S. 69 (7th Street) north and Riverview in Kansas City. 11/03/16

East North at

Interstate 70/U.S. 24-40 splits with I-670 a mile after the cloverleaf interchange (Exit 420A) bringing U.S. 69 northbound onto the freeway from the 18th Street Expressway. 06/19/15

References

1. "6-Lane Link to Tie Freeway and I70." The Fort Scott Tribune (KS), December 29, 1971.
2. Kansas Department of Transportation. Kansas Interstate 50th Anniversary. Retrieved from https://www.ksdot.org/interstate50th/default.asp
3. "Interstates show wear of 35 years More traffic, stress of weather, heavy trucks damage nation's roads." The Kansas City Star (MO), August 4, 1991.
4. "I-670 project wins top award from Consulting Engineers Council." The Kansas City Star (MO), March 31, 1991.
5. "City breaks ground on Bartle expansion But building over freeway and finishing in time for the first convention are top concerns." Kansas City Star, The (MO), October 25, 1991.
6. "Bartle Hall begins its next expansion." Kansas City Star, The (MO), June 18, 2005.
7. "Bartle Hall basks in the spotlight of expansion opening." Kansas City Star, The (MO), September 24, 1994.
8. "Downtown routes will change this week." Kansas City Star, The (MO), January 2, 2006.
9. "With bridges open, downtown will get a little easier to navigate." Kansas City Star, The (MO), October 4, 2007.