Interstate 670 Kansas / Missouri

Interstate 670 travels east along an elevated viaduct over the West Bottoms industrial area to Quality Hill outside Downtown Kansas City, Missouri. 06/19/15

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.

I-670 (Dillingham Freeway) westbound ahead of the exchange with Interstate 35 by the Sprint Center in Downtown Kansas City. 10/07/21

Route Information

West End – Kansas City, KS
East End – Kansas City, MO
Total Mileage – 2.81

Kansas – 1.64

Cities – Kansas City
Junctions –

Missouri – 1.17

Cities – Kansas City
Junctions –

Source: December 31, 2021 Interstate Route Log and Finders List

The south leg of the Alphabet Loop defaulted traffic onto Interstate 35 (Southwest Trafficway) to the west. Downtown Kansas City – 1969.

Interstate 35 utilized the I-670 freeway to make the connection with the Southwest Trafficway from the Midtown Freeway until the west leg of the Alphabet Loop was completed.

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

Photo Guides

Kansas / Missouri

East End – Kansas City, Kansas

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

Passing below a pedestrian bridge by the Sprint Center, I-670 advances to within one quarter mile to Exit 2 N for I-70 (unsigned here) west / U.S. 71 north to I-29/35 north. I-29 commences a 755 mile long route to Pembina, North Dakota (south of Winnipeg, Manitoba) 0.7 miles to the north at Exit 2 G. 10/07/21

An end sign for I-670 precedes the Holmes Street overpass as Exit 2 N partitions for I-70/U.S. 24-40 west and U.S. 71 north. U.S. 71 accompanies I-29 north to St. Joseph. 10/07/21

Exit 2 M links with Bruce Watkins Drive, a partial freeway leading U.S. 71 south to the Three Trails Crossing Memorial Highway exchange with I-49/435/470. U.S. 71 south from Grandview to Pineville was redesignated as I-49 in December 2012. 10/07/21

The remainder of I-670 east extends to The Paseo at Exit 3 A, where Interstate 70 overtakes the freeway. 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

Interstate 70 descends below street level as it passes by Exit 3 C for Prospect Avenue, one mile ahead of I-670 and U.S. 71. 05/07/22

I-70/U.S. 24-40 travel west from Independence Plaza to Paseo West and the split with Interstate 670 at Left Exit 2 L. 05/07/22

High rises from Downtown Kansas City come into view as Exit 3 A leaves for The Paseo. I-70/U.S. 24-40 west combine with U.S. 71 north at the east end of I-670. U.S. 71 enters the exchange from Bruce Watkins Drive and Hospital Hill. 05/07/22

The westbound mainline of I-70 transitions directly onto I-670 ahead of the Sprint Center. I-670 continues west to the Kansas City Convention Center and West Bottoms industrial area. 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

I-70/U.S. 24-40 east and U.S. 71 south separate at Exit 2 M just ahead of I-670 (Dillingham Freeway). 10/07/21

U.S. 71 shifts to the Midtown South Freeway beyond Exit 2 L for I-670 southward through Hospital Hill en route to Interstate 49. 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

Traffic partitions with a single lane left exit for I-670 west toward Kansas City, Kansas, the continuation of U.S. 71 north onto I-70/U.S. 24/40 west and I-70/U.S. 24-40 east toward Independence. 11/03/16

East End Throwback

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

Exit 3A drops from I-70 west to The Paseo and the surface street connection to U.S. 71 south. Signs for Exit 2L omitted Interstate 670 at this time. 10/17/04

The speed limit drops to 45 mph as Interstate 70 enters the Central Business District area. There are several close exit and entrance ramps on the pending stretches of I-670 and I-70, all part of the Alphabet Loop exit numbering scheme. 10/17/04

Prior to the completion of Interstate 670 west into Kansas City, Kansas, the south leg of the Alphabet Loop was signed as simply a connection to I-35 south to Wichita. Photo by Michael Summa (1982).

An arrow per lane sign replaced this set of overheads on I-70-U.S. 40 east and U.S. 71 south ahead of Exit 2L to Interstate 670. Joplin was added for U.S. 71 south, reflecting the 2012 designation of Interstate 49. Photo by Jeff Morrison (05/14/07).

West End – Kansas City, Kansas

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

I-670 (Dillingham Freeway) runs along a viaduct across the Kansas River to the wye interchange with I-70/U.S. 24-40 west at Armourdale in Kansas City, Kansas. 05/07/22

An end shield for Interstate 670 stands at the Mill Street overpass. U.S. 69 combines with I-70/U.S. 24-40 west from adjacent 7th Street to the 18th Street Expressway. 06/18/15

An end shield for Interstate 670 stands at the Mill Street overpass. U.S. 69 combines with I-70/U.S. 24-40 west from adjacent 7th Street to the 18th Street Expressway. 10/17/04

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

Three lanes separate from I-70 east at Left Exit 421B for Interstate 670 into Kansas City, Missouri. I-70 turns north with two through lanes along side the Kansas River toward Downtown Kansas City, Kansas. 06/19/15

Traffic separates for Interstate 670 eastbound beyond the S 10th Street overpass at the Armourdale neighborhood in Kansas City. Although it provides a more direct route through Downtown Kansas City over I-70, there are no control cities for the urban loop. 06/19/15

I-70 heads east from Downtown Kansas City across the Lewis and Clark Viaduct into Missouri. I-670 runs across the south side of the West Bottoms industrial area between the Kansas River and Downtown Kansas City, Missouri. 06/19/15

Sources:

“6-Lane Link to Tie Freeway and I70.” The Fort Scott Tribune (KS), December 29, 1971.
Kansas Interstate 50th Anniversary.
“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.
“I-670 project wins top award from Consulting Engineers Council.” The Kansas City Star (MO), March 31, 1991.
“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.
“Bartle Hall begins its next expansion.” Kansas City Star, The (MO), June 18, 2005.
“Bartle Hall basks in the spotlight of expansion opening.” Kansas City Star, The (MO), September 24, 1994.
“Downtown routes will change this week.” Kansas City Star, The (MO), January 2, 2006.
“With bridges open, downtown will get a little easier to navigate.” Kansas City Star, The (MO), October 4, 2007.

Page updated July 1, 2022.