Before the construction of I-70, there were two routes between Kansas City and St. Louis, US 40 via Columbia and US 50 further south via Jefferson City, the capital of Missouri. Ultimately, it was decided not to have I-70 run via Jefferson City, but further north via Columbia, in the corridor of US 40. The main reason is that this was an easier route, US 40 mostly runs through flat terrain while US 50 more through hilly terrain around the Missouri River, particularly between Jefferson City and St. Louis.

• SEARCHFORPUBLICSCHOOLS: Provides a list of all public primary and high schools in Missouri, including street address, contact phone, and zip code for each school.

Construction history

Construction on Interstate 70 in Missouri began on August 13, 1956, around St. Charles, just west of St. Louis, an area that was then rural. The Blanchette Bridge was the first new bridge of the Interstate Highway system. The rest of the highway was built fairly quickly after that, because of the priority that this corridor had between Kansas City and St. Louis. The highway between the two cities was completed in 1966 when the last section opened in Russell County. Before I-70 opened, it took 8 hours to drive from Kansas City to St. Louis, the construction of Interstate 70 made it possible in half the time. The section in what are now the suburbs of St. Louis was completed in the late 1950s, the section through St. Louis itself opened to traffic in the early 1960s. On November 9, 1967, the Poplar Street Bridge in St. Louis opened over the Mississippi River. The Blanchette Bridge over the Missouri River at St. Charles opened in two phases, the first span in 1958 and the second in 1978.

• USPRIVATESCHOOLSFINDER.COM: Provides a list of all private primary and elementary schools in Missouri, including street address, contact phone, and zip code for each school.

Later adjustments

I-70 has express lanes in St. Louis, originally a 2-lane toll-free interchangeable lane. This alternating lane was constructed immediately during the construction of I-70 in the early 1960s and was opened to traffic on August 22, 1961. This may have been the first alternating lane on a motorway in the world. Between 1998 and 2003, I-70 through St. Louis was modernized with all bridges replaced. The interchange was then closed for 5 years. Since December 2011, the interchangeable lane has been in permanent use towards the center and has been renamed to an express lane.

On February 9, 2014, the Stan Musial Veterans Memorial Bridge opened over the Mississippi River in St. Louis. The bridge shortens the distance from Interstate 70 in the state of Missouri by 2 kilometers. Since then, I-70 no longer runs along Downtown St. Louis, that route has since become I-44.

The Lewis and Clark Viaduct in Kansas City was completely replaced between 2018 and 2020 and was closed to the west for two years.

Between 2021 and 2024, I-70’s bridge over the Missouri River at Rocheport was replaced. The original bridge was sub -standard, this was a steel truss bridge with only 2×2 lanes and no emergency lanes. The bridge has been replaced by two 3-lane spans and an emergency lane, preparing for the planned widening of I-70 through Missouri. Construction began on October 12, 2021 and lasted until the end of 2024. The project cost $240 million.

Opening history

Van	Unpleasant	Length	Opening
Exit 175	Exit 224	79 km	1958
Exit 228	Exit 234	10 km	09-1958
Exit 242	Exit 244	3 km	09-1958
Exit 248	Exit 250	3 km	03-1959
Exit 124	Exit 128	6 km	1959
Exit 224	Exit 228	6 km	1959
Exit 98	Exit 124	42 km	1961
Exit 243	Exit 248	7 km	28-07-1961
Exit 234	Exit 243	14 km	22-08-1961
Exit 37	Exit 49	19 km	1962
Exit 58	Exit 66	13 km	1962
Exit 128	Exit 148	32 km	1962
Exit 0	Exit 6	10 km	1963
Exit 5	Exit 11	10 km	1964
Exit 49	Exit 58	14 km	1964
Exit 66	Exit 98	51 km	1964
Exit 250	Exit 251	2 km	1964
Exit 11	Exit 37	42 km	1965
Exit 148	Exit 175	43 km	1965
Exit 251	Exit 252	1 km	1967*

* renumbered to I-44 in 2014.

Future

Verbreding Kansas City – St. Louis

For years, there has been a desire to widen I-70 between Kansas City and St. Louis in its entirety because of the high proportion of freight traffic. Various ideas have been suggested in the past, such as separate truck lanes. These are called “dedicated truck lanes” (DTL) and will have 2×2 lanes in the median strip with fewer connections. The highway will then have 4×2 lanes throughout Missouri. The number of trucks across the entire corridor was expected to increase from 10,000 to 25,000 trucks per day. Ultimately, the system would have to run all the way from Kansas City to Ohio. The cost was estimated at $2 – 4 billion and funding has not yet been found. It has been proposed several times to turn I-70 into a toll road.

Traffic intensities

I-70 in Kansas City.

The bridge over the Missouri River at Rocheport (replaced 2021-2024).

I-70 at Foristell, just west of St. Louis.

#	2013
Kansas state line	68.000
Exit 2A south	70.000
Exit 2G north	92.000
Exit 2L	95.000
Exit 7	80.000
Exit 8	100.000
Exit 11	112.000
Exit 15	95.000
Exit 20 Blue Springs	70.000
Exit 28 Oak Grove	36.000
Exit 37 Odessa	29.000
Exit 49 Higginsville	19.000
Exit 66 Sweet Springs	23.000
Exit 78 Marshall	26.000
Exit 98 Arrow Rock	24.000
Exit 101 Boonville	28.000
Exit 106 Boonville	32.000
Exit 117 Huntsdale	31.000
Exit 121 Columbia	46.000
Exit 125 Columbia	73.000
Exit 128 Columbia	38.000
Exit 148 Mexico	31.000
Exit 175 New Florence	31.000
Exit 188 Truxton	34.000
Exit 200 Wright City	50.000
Exit 208 Wentzville	71.000
Exit 210	75.000
Exit 217 O’Fallon	117.000
Exit 220 St. Peters	139.000
Exit 224	115.000
Exit 228 St. Charles	138.000
Exit 229 St. Charles	155.000
Exit 231 Maryland Heights	141.000
Exit 232	116.000
Exit 238	130.000
Exit 241 Northwoods	115.000
Exit 243 St. Louis	92.000
Exit 249	47.000

Lane Configuration

Van	Unpleasant	Lanes	Comments
Exit 0	Exit 2M	2×3	Kansas City
Exit 2M	Exit 3C	2×4	Kansas City
Exit 3C	Exit 20	2×3	Kansas City
Exit 20	Exit 214	2×2
Exit 214	Exit 228	2×3	St. Louis
Exit 228	Exit 232	2×5	St. Louis
Exit 232	Exit 244	2×3	St. Louis
Exit 244	Exit 249	3+2+3	St. Louis
Exit 249	Exit 250	2×3	St. Louis