Shortest Interstate in the US, and All 77 Ranked by Length

What is the shortest interstate in the US?

It depends what you count as an interstate.

• Shortest main route: H-2 on Oahu, Hawaii, which runs from Pearl City to Wahiawa. The Federal Highway Administration (FHWA) route log gives it 8.32 miles [5].
• Shortest main route on the mainland: I-97 in Maryland, between Annapolis and Glen Burnie, at 17.62 miles in the FHWA log [5]. The North Carolina section of I-87, signed in 2017 between Raleigh and Wendell, is shorter still at about 13 miles on the Alan’s Factory Outlet chart above, but it shares its number with the much longer I-87 in New York, so official logs do not treat it as a separate route.
• Shortest two-digit route of any kind: I-69W in Laredo, Texas, at 1.40 miles, one of the branches of the I-69 corridor [2].
• Shortest interstate including three-digit spurs: I-878 in Queens, New York, at 0.70 miles. It is unsigned and forms part of the Nassau Expressway [2][6].

Hawaii’s three interstates, H-1, H-2 and H-3, are all short because they serve a single island. They were funded as part of the system to link military bases and the communities around Honolulu, which is why an island state has interstates at all [2].

What is the longest interstate in the US?

I-90 is the longest, running 3,020 miles from Seattle, Washington, to Boston, Massachusetts, through 13 states [2][3]. Wikipedia’s Interstate Highway System article gives it 3,020.54 miles, though its own I-90 article uses a longer figure, so expect small differences between sources [2][3].

The rest of the top five on the chart are I-80 from San Francisco to Teaneck, New Jersey (2,900 miles), I-40 from Barstow, California, to Wilmington, North Carolina (2,557 miles), I-10 from Santa Monica to Jacksonville, Florida (2,460 miles), and I-70 from Cove Fort, Utah, to Baltimore (2,151 miles) [1]. The longest north to south route is I-95, at about 1,908 miles from Miami to the Canadian border at Houlton, Maine [2].

The longest and shortest interstates compared

Interstate	From	To	Length (miles)
I-90	Seattle, WA	Boston, MA	3,020
I-80	San Francisco, CA	Teaneck, NJ	2,900
I-40	Barstow, CA	Wilmington, NC	2,557
I-10	Santa Monica, CA	Jacksonville, FL	2,460
I-70	Cove Fort, UT	Baltimore, MD	2,151
H-1	Kapolei, HI	Honolulu, HI	27
I-14	Copperas Cove, TX	Belton, TX	25
I-97	Annapolis, MD	Glen Burnie, MD	18
H-3	Halawa, HI	Marine Corps Base, HI	15
H-2	Pearl City, HI	Wahiawa, HI	8

Lengths are from the chart and rounded [1]. Newer routes grow as sections open: the FHWA log now gives I-11 in Nevada 54.19 miles, more than twice the 23 miles on the chart, so treat any ranking of the shortest routes as a snapshot [5].

How interstate numbers work

The numbers tell you which way a route runs and roughly where it is [2]:

• Odd numbers run north and south, rising from west to east, from I-5 on the West Coast to I-95 on the East Coast.
• Even numbers run east and west, rising from south to north, from I-10 along the southern border to I-90 and I-94 in the north.
• Numbers divisible by 5 (I-5, I-10, I-95 and so on) are meant to be the major long-distance arteries.
• Three-digit numbers are auxiliary routes off a main route, mostly in cities. An odd first digit means a spur that joins the system at one end only; an even first digit means a bypass or beltway connected at both ends.

There are many exceptions. Some numbers are used twice in different parts of the country, such as I-76, I-84, I-86 and I-88, each with an eastern and a western route, and I-87 in New York and North Carolina [1][2]. Alaska and Puerto Rico’s interstate-funded highways do not follow the rules at all and carry the prefixes A and PR [2].

When the interstate system was built

The Interstate Highway System was created by the Federal-Aid Highway Act, signed by President Dwight D. Eisenhower on 29 June 1956, and is officially named after him [2]. 1957 was the busiest year for new routes on the chart, with 11 interstates designated [1].

The original system was declared complete on 14 October 1992, when I-70 opened through Glenwood Canyon in Colorado. It took 35 years and cost $114 billion against an original estimate of $25 billion over 12 years [2]. New routes are still being added, including I-22 in Mississippi and Alabama in 2012, I-41 in Wisconsin in 2015 and I-11, I-14 and the North Carolina I-87 in 2017 [1]. The system now totals about 48,890 miles [2].

Interstate records

• Most states: I-95 passes through 15 states plus the District of Columbia [2].
• Most interstate miles in one state: Texas, with about 3,233 miles on 17 routes [2].
• Longest stretch inside one state: I-10 runs 877 miles across Texas from El Paso to Orange [2].
• Highest point: 11,158 ft on I-70 in the Eisenhower Tunnel in Colorado [2].
• Busiest: I-405 in Los Angeles, at about 379,000 vehicles a day in 2019 [2].

Questions about the shortest interstate in the US

What is the shortest interstate in America?

Among main routes, H-2 in Hawaii at 8.32 miles [5]. Counting three-digit spur routes, I-878 in New York is shorter at 0.70 miles [2].

What is the shortest interstate on the mainland US?

I-97 in Maryland, at 17.62 miles between Annapolis and Glen Burnie, is the shortest standalone mainland main route in the FHWA log [5]. The North Carolina I-87 section is shorter but shares its number with the New York route.

What is the longest interstate?

I-90, at about 3,020 miles from Seattle to Boston [2].

What is the second longest interstate in the US?

I-80, from San Francisco, California, to Teaneck, New Jersey, at about 2,900 miles across 11 states [1][4].

Which state has the most interstate highways?

New York has the most interstate routes, 32 including spurs, while Texas has the most interstate mileage, about 3,233 miles [2].

Sources

1. Alan’s Factory Outlet, The Longest (and Shortest) Interstate Highways Across the United States, the original infographic.
2. Wikipedia, Interstate Highway System.
3. Wikipedia, Interstate 90.
4. Wikipedia, List of primary Interstate Highways.
5. Federal Highway Administration, Route Log and Finder List, Table 1, main routes as of January 2026.
6. Wikipedia, New York State Route 878.

Last reviewed 2 November 2026