Interstate 270 (Illinois–Missouri)

Interstate 270 (I-270) makes up a large portion of the outer belt freeway in the St. Louis, Missouri metropolitan area. The counterclockwise terminus of I-270 is at the junction with Interstate 55 in Mehlville, Missouri; the clockwise terminus of the freeway is at the junction with I-55 and I-70 north of Troy, Illinois. The entire stretch of I-270 is 50.59 miles (81.42 km).

Interstate 270 between Interstate 70 and Interstate 55 was formerly designated Interstate 244, a Western bypass of St. Louis, Missouri. It was originally proposed by Missouri as Interstate 144, but the road was a beltway (or part of one), so the AASHTO assigned it the number "244". By the late 1970s, the entire beltway (including today I-255) was integrated as a part of "270" for consistency. However, the politicians in Illinois started planning their supplemental freeway system in the mid 1970s and somehow a 5 mile section of "Corridor 413" was included into the Interstate Highway System in April 1978.^[2] This caused a potential place of confusion in Pontoon Beach, Illinois where I-270 would have intersected itself, and eventually IDOT decided on the 255 numbering in 1980 (but not before considering renumbering a 8 mile section to I-870).

History

The section of I-270 on the Missouri side was completed by June 1964, while the section that was I-244 was completed by November 1968.^[3] The section from IL Route 3 to I-55 in Illinois was finished by May 1965.^[4]

During the Great Flood of 1993, the New Chain of Rocks Bridge carrying I-270 over the Mississippi River was the only bridge open from St. Louis to Keokuk, Iowa at one point. (All other bridges from the McKinley Bridge to the Keokuk Bridge were closed at the peak of that flood.)

The last major construction project on I-270 occurred from 1995-1998. Both the Missouri Department of Transportation and the Illinois Department of Transportation upgraded I-270 to modern standards from Lilac Ave. to I-255. However, this section of I-270 is still at 2 lanes in each direction.

On September 13, 1999, a fatal accident involving a tractor-trailer occurred in the westbound lanes of I-270^[5] in front of the now-defunct St. Thomas Aquinas-Mercy High School (now North County Christian School) in North St. Louis County. This accident sped up efforts that led to the I-170/270 interchange reconstruction that went from 2001 to 2004.

A major accident and fire from a FedEx truck between the Route 367 and Lilac exits on October 28, 2002 forced detours and lengthy delays.^[6][7]

There were plans to sign an eight mile (13 km) section of I-270 from Glen Carbon to Edwardsville as I-870. However, this idea was discarded.^[8]

In 2008 MODOT Implemented new Variable speed limits on I-270/255 with the normal limit being 60 mph (97 km/h).^[9] However, due to complaints from the public, these signs will be tweaked in 2011 to advisory signs^[10].

Future

IDOT wants to widen I-270 from Lilac to I-255 from four lanes to six, but no money is available at the current time.^[11] However, IDOT has announced that nearly $100 million has been programmed for replacement of the canal bridges between 2011 and 2016.^[12]

MoDOT has also identified the need of improving the I-270 corridor in North St. Louis County, which could cost in the range of $200M.^[13]

A 5 mile section of I-270 between I-44 and Manchester is due to be widened to 5 lanes in each direction, with work taking place between 2012-2013^[14] This section of 270 sees up to 175,000 vehicles per day^[15], and peak hour congestion is common.

Route description

I-270 starts at I-55 as a 10 lane freeway but goes down to 8 lanes at the first exit for Tesson Ferry Road. The interstate remains at 8 lanes (4 in each direction with occasional mandatory exit lanes) through Manchester as the highway transforms into a true north-south highway and it is signed as such. I-270 meets up I-44 in a modified cloverstack interchange that was rebuilt in the 1990s. Railroad overpasses and rocky bluffs between I-44 and Manchester keep the interstate at 8 lanes and this section is known for frequent traffic tie-ups during peak hours. I-270 meets up with I-64 (usually referred as Highway 40) with a stack interchange that was built from 1987 to 1993 (it was previously a cloverleaf that was a frequent source of backups). From that point through I-70, it becomes a 10 lane interstate again, although the right lanes often serve as exit lanes. The intersection with Olive was upgraded to a SPUI in the mid 2000s, and during 2010-2011, the interchanges with Page and Dorsett is being upgraded (with the latter being a diverging diamond). Congestion in this area is severe to the point MoDOT has spent millions on various traffic control improvements since the 1990s. One of the safety improvements is a "double white line" that motorists are not permitted to cross (violation of that could lead to a fine of $500 USD) that is located at the exits for I-70 in the northbound lanes. Other safety implementations include a special Maryland Heights police cruiser that is dedicated to traffic enforcement just on this section of 270, congestion warning signs, and traffic cameras.

At I-70, 270 makes a transition from a north/south highway to a east/west highway (though not signed as such until McDonnell), and will eventually become a 6 lane highway by the time it reaches Lindbergh. It then meets I-170, which had its interchange rebuilt from 2001-2004 (the old layout had a left exit in the westbound lane, the new configuration got rid of the left exit). This section of 270 was a source of frequent backups during the late-afternoon hours until the interchange was rebuilt. A fatal accident in September 1999 spurred the rebuilding of the interchange although the accident did not occur at that location (it happened a mile east of the interchange). I-270 then passes various streets where every westbound exit connects to Dunn Road and one must use Dunn Road to access 270 (only exceptions being Riverview, Lilac, and Route 367). Since Dunn Road still handles 2 way traffic, this has become a safety and congestion issue that MoDOT wants to address in the near future.

At Lilac, I-270 transform into a 4 lane highway as it crosses the Mississippi River on the "new" Chain of Rocks Bridge. As it enter Illinois, it makes a drastic transition from a urban interstate to a rural interstate with farm fields still dotting the landscape. The speed limit drops to 55 MPH for the next 8 miles. As it crosses the river and enter Choateau Island, both sides of the highway are tree-lined. Once it crosses the Chain of Rocks Canal, 270 will intersect 3 different state highways in cloverleaf interchanges (with the second one using a collector-distributor system with 2 folded diamonds). Once it passes IL 111, the speed limit increases to 65 as the highway briefly becomes 6 lanes again with the junction with 255. Past 255, the highway reverts back to a 4 lane highway with diamond interchanges with IL 157 and IL 159 before meeting up with I-55/70 at the interchange that IDOT refers as the "3 I's". If you continue east on I-70, you will notice the next mile marker is 16, which correspond with I-270 mileage in Illinois.

Popular Culture

This highway is referenced in Chingy song "Holidae In" although 270 does not intersect Natural Bridge Road.

Exit list

The exits are numbered in a clockwise direction beginning at the I-55/I-255 intersection.

References