Interstate 75 in Michigan

Interstate 75 (I-75) is a part of the Interstate Highway System and runs from Miami, Florida to Sault Ste. Marie in the Upper Peninsula of Michigan. I-75 enters the state from Ohio in the south, just to the north of Toledo. It runs generally north through Detroit, Pontiac and Bay City, crossing the Mackinac Bridge and ending at the Canadian border in Sault Ste. Marie. On the Canadian side, drivers must use a series of city streets in Sault Ste. Marie, Ontario to reach Highway 17, the local route of the Trans-Canada Highway. The total length in Michigan is 395 miles (636 km).

Route description

I-75 connects Michigan's Upper and Lower Peninsulas via the 5-mile (8.0 km) long suspension Mackinac Bridge.

At the northern end of I-75, at Sault Ste. Marie, Michigan, the Sault Ste. Marie International Bridge leads into Canada, into Sault Ste. Marie, Ontario. This is the closest connection of any Interstate to the Trans-Canada Highway.

In Detroit, the spur route I-375 is the shortest signed spur of I-75 at 1.06 miles (1.71 km). Interstate 375 is the shortest signed Interstate Highway. In addition, at that same junction, the I-75 curve where it shifts from the Fisher Freeway to the Chrysler Freeway is one of the sharpest on a mainline route in the entire Interstate system, with a 25 mph (40 km/h) advisory speed.

Names

• The section in Cheboygan County from the southern end of the Mackinac Bridge to the south is known as the G. Mennen Williams Freeway.
• The section from the northern end of the Mackinac Bridge in Mackinac County proceeding north is known as the Prentiss M. Brown Freeway.
• The section between downtown Detroit and Pontiac is known as the (Walter P.) Chrysler Freeway. It is one of busiest segments of I-75 and hosts one of the perennially busiest segments of freeways in Michigan. The Chrysler Freeway continues south as I-375.
• The section through Southern and central Detroit to the Chrysler Freeway is known as the Fisher Freeway
• The section south of the Fisher Freeway is called the Detroit–Toledo Freeway south to the Ohio state line.

History

Pre designation

Prior to any segment of freeway in Michigan being designated as part of Interstate 75 various sections of it had been constructed.

Between the mid and late 1950s the following sections were constructed:

• US 2 between what is now known as BL I-75 in St. Ignace and M-123 was the Upper Peninsula's first segment.
• Alt US 24 between Ohio border and US 25 (now M-125) was the first segment of Michigan's I-75 to cross the state border; and the only freeway to cross the border until the early 1960s.
• Mackinac Bridge (on what was then US 27) was completed in 1957.
• M-20 (now part of US 10) - when this segment became US 10; it carried the temporary Interstate 75 designation.

This transport-related list is incomplete; you can help by expanding it.

Post designation

In 1960 the Zilwaukee Bridge, a Bascule bridge across the Saginaw River was constructed.^[2]

In the 1960s, I-75 had several discontiguous segments connected with roads with "TO I-75" signs in addition to US 10 doubling as "TEMP I-75".

The section between Grayling, Michigan and M-32 was built in 1961. Between Higgins Lake and Grayling, it was built by converting the northbound lanes of U.S. Route 27 to southbound lanes and building a new set of northbound lanes leaving the former southbound lanes as a strip of grass. The terminus of the freeway near downtown Grayling was converted to a partial interchange for what would become BL I-75. Alongside that, the former segment of US 27 between Grayling and Gaylord, Michigan was turned back to local control. After this individual segment of freeway was completed, it left a gap between Gaylord and Indian River which was filled in a year later. While the gap was being filled in, a special "TO I-75" designation was applied to the former segment of US 27. Around that time, US 27's northern terminus was scaled back to 5 miles (8.0 km) south of Grayling until it was redesignated as an extension of US 127 in 2001.

A 12-mile (19 km) section of I-75 was opened between Gaylord and Waters in July 1962.^[3]

In Detroit the Fisher Freeway was built in 'the early 1960s'^[4] and then the Chrysler Freeway in 1967.^[5]

Until the early 1970s, I-75 between Bay City and Grayling was routed west to Clare (along US-10 then north along then-US-27, and was signed as "TEMP I-75". This freeway segment had some at-grade intersections at the time. In 2002 the portion between Clare and Grayling was redesignated as an extension of US 127, although it was posted as US 127 on a National Geographic road atlas in the year 2000.

The section between Alger and Roscommon was completed in 1973, and the temporary section reverted to U.S. routes, although of freeway quality.

Until the completion of I-75 in 1973, the stretch of freeway between Standish and West Branch had the designation of M-76. When the I-75 signs were erected along the freeway, M-76 vanished from the state road map after 53 years of existence.

In the 1988 the original bascule Zilwaukee Bridge across the Saginaw River was replaced by a much higher structure slightly north of the former bridge.^[2]

Until 1987, US 10 and I-75 were the same road between Bay City and Clarkston. Both also overlapped US 23 between Bay City and Flint. Now, Bay City serves as the eastern terminus of US 10.

As late as 1990, US 31 and US 23 both had their northern termini on I-75's southern approach to the Mackinac Bridge. Even though US 27 was scaled back 94 miles (from Mackinaw City to south of Grayling) in 1961, a lone sign assembly showed all three US highways ending at the same place as late as 1971.

Late 2000s

Beginning on February 25, 2008, the Interstate closed completely to traffic in both directions from Rosa Parks Boulevard (Exit 49) to Clark Street (Exit 47) in Detroit.^[6] This facilitated the complete rebuilding of the road as part of the Gateway Project to better connect Interstates 75 and 96 to the Ambassador Bridge. Through traffic on 75 was instructed to take I-94 to I-275 and local detours were posted. The freeway re-opened to through traffic in July 2009, hence about all of the signs on I-75 within Detroit's city limits are in the Clearview typeface.

Spur routes

• I-275 - Begins as a loop from Northern Monroe County and continues to connect up with Interstate 696. Was going to connect back up with I-75 north of Pontiac. Serves the Western population of Wayne County and Detroit Metro Airport.

• I-375 - Is the shortest signed Interstate in the nation. It serves the immediate downtown Detroit area.

• I-475 - Known as the U.A.W. Freeway. Serves Flint's downtown areas as I-75 goes to the west side of the city.

• I-675 - A loop into the city of Saginaw and back out north of the city. Served as an alternate to I-75 when the drawbridge over the Saginaw River was still operating.

Exit list

See also

• Michigan Highways portal

References

External links

• I-75 at Michigan Highways
• Interstate 75 at Michigan Highway Ends