Interstate 70 (I-70): Route, Mileage, Crash and Bridge Data

How long is I-70?

The FHWA Route Log credits I-70 with 2,061.22 miles as of January 2026. Only I-80, I-90, I-40 and I-10 carry more. Colorado has the longest piece at 450.18 miles, with Kansas close behind at 423.68, and West Virginia the shortest at 14.45.

Interstate Guide prints a longer total, 2,150.57 miles, because it counts pavement that I-70 shares with other routes. The Route Log assigns those shared miles to the other route. Pennsylvania shows the biggest gap: 87.22 miles on the Pennsylvania Turnpike go to I-76 and 3.55 miles near Washington go to I-79, so the state row reads 80.71 miles, and adding the shared miles back gives about 171. Illinois loses 16.00 miles shared with I-55 east of St. Louis and 5.59 shared with I-57 at Effingham. The overlaps with I-65 in Indianapolis and I-71 in Columbus are each about two miles. The single mile shared with I-35 in Kansas City stays in I-70's Missouri row.

Where I-70 starts and ends

The western end is the junction with I-15 near Cove Fort, Utah. The original 1957 plan started I-70 in Denver; the extension to Cove Fort was announced that October to give Southern California traffic a road east. The eastern end is I-695, the Baltimore Beltway, in Woodlawn, Maryland. Plans to carry I-70 into Baltimore to meet I-95 were dropped after neighborhood opposition, and in 2014 the route was cut back to the beltway. The short freeway east of I-695 is now MD 570.

From Utah the road crosses the Rockies to Denver, then runs through Topeka, Lawrence, Kansas City, Columbia, St. Louis, Terre Haute, Indianapolis, Columbus and Wheeling before reaching Frederick and the Baltimore area. In Utah it goes 110 miles between Salina and Green River with no motorist services.

Interstate junctions along I-70

The list starts at I-15 in Utah and runs east. I-76 appears once in Colorado and twice in Pennsylvania. They are two unrelated roads with the same number: one heads from Denver toward Nebraska, and the other is the Pennsylvania Turnpike, which I-70 joins at New Stanton and leaves at Breezewood. I-55 shows twice in Illinois, at each end of the stretch the two routes share.

Fatal crashes on I-70

Fatal crashes on I-70 killed 748 people from 2020 to 2024, about 150 a year. The count jumped from 120 in 2020 to 172 in 2021, then slid each year to 144 in 2024. Measured against its length, I-70 has 6.9 deaths per 100 route miles a year, below the Interstate average of 9.5. That puts it 33rd of the 56 routes long enough to rank.

Missouri stands out. Its 249.36 miles had 171 deaths, a rate of 13.7, the highest of any I-70 state, and three Missouri counties lead the county list: Jackson County in Kansas City with 39, the city of St. Louis with 28 and St. Charles County with 24. Marion County, Indiana, and Franklin County, Ohio, which hold Indianapolis and Columbus, follow at 22 each. Colorado had slightly more deaths than Missouri, 173, but spread over 450 miles its rate is 7.7. Maryland's rate is 11.3. Pennsylvania is lowest at 2.4, counted over the roughly 171 miles I-70 runs there, Utah is next at 2.9, and West Virginia's short stretch is too small for a rate.

Counties with the most I-70 crash deaths

Bridges on I-70

The 2025 National Bridge Inventory lists 1,913 bridges carrying the I-70 main line, with a median build year of 1967. Colorado has the most, 422, and it also has the most rated Poor: 30 of the route's 67. Illinois is next with 14 Poor out of only 119 bridges. Across the whole route about 3.5 percent rate Poor, and Utah and Pennsylvania have none.

St. Louis moved I-70 to a new Mississippi River crossing in 2014. The Stan Musial Veterans Memorial Bridge opened on February 9 of that year, taking the route off the Poplar Street Bridge, open since 1967.

Tolls on I-70

FHWA's toll inventory from January 2023 lists three facilities on I-70. A through trip east from Utah pays twice: on the Kansas Turnpike between Topeka and Kansas City, and on the Pennsylvania Turnpike from New Stanton to Breezewood, which FHWA measures at 86.11 miles. FHWA's 236 miles for Kansas is the whole turnpike from the Oklahoma line, and most of it carries other routes, chiefly I-35. The third entry is Colorado's Mountain Express Lanes, shoulder lanes that open as priced lanes at busy times: 13 miles eastbound, plus about 12 miles westbound from Idaho Springs to Empire, tolled since July 2022.

At Breezewood, I-70 leaves the turnpike and runs a short stretch of US 30 with traffic lights before resuming as a freeway. The gap goes back to the 1956 highway act: federal money for a direct ramp would have required the Turnpike Commission to agree to end tolls once its bonds were paid, which the commission did not want. The Turnpike began engineering a direct connection in 2026, with construction planned for 2033 to 2035. In Denver, express lanes on the rebuilt Central 70 section started charging on July 11, 2023, after FHWA's inventory date. They run 10 miles each way between I-25 and Chambers Road, and the general lanes beside them stay free.

I-70 auxiliary routes

Five three-digit numbers carry I-70's number, and three of them are used more than once. I-270 is four separate roads: a short connector in the Denver area, the St. Louis bypass that crosses into Illinois, the loop around Columbus, and the Maryland spur from Frederick to the Capital Beltway at Bethesda. I-470 is a road in Topeka, a loop through Lee's Summit and Independence near Kansas City, and a Wheeling bypass that crosses into Ohio. I-670 is a downtown connector in both Kansas City and Columbus. I-170 in St. Louis County and I-370 at Gaithersburg are single roads.

When I-70 was built

Missouri and Kansas both claim the first Interstate project. Missouri awarded a contract on August 2, 1956, for a section in St. Charles County and started work on August 13. Kansas opened a two-lane section west of Topeka on November 14, 1956, signed as the first project completed under the new federal highway act. I-70 itself was designated on August 14, 1957.

The western mountains took decades. In Utah, about 70 miles of two-lane road opened at once on November 5, 1970, and the second Eagle Canyon bridge in the San Rafael Swell completed four lanes in 1990. In Colorado, the first bore of the Eisenhower Tunnel was dedicated on March 8, 1973, and the second, the Johnson bore, was finished on December 21, 1979. The tunnel's west portal sits at 11,158 feet. The last new section opened on October 14, 1992: 12 miles through Glenwood Canyon, built for $490 million. In August 2021, debris flows off slopes burned by the 2020 Grizzly Creek Fire shut I-70 in the canyon; it partly reopened on August 14.

Missouri is adding lanes to its stretch in phases. A $600 million contract, the largest in MoDOT's history, adds a third lane each way between Warrenton and Wentzville, with ground broken on March 20, 2025.

I-70 traffic and road conditions

Most people who search for I-70 want to know about a closure or a crash today, and the state DOT traveler maps post those as they happen. Links are below, from west to east.

I-70 questions