Tuesday, January 10, 2012

New bridge, diverging diamond interchange to be built at I-44 and Rangeline

(From MODOT)

A public meeting to provide details about a 2012-13 project to rebuild the Interstate 44/Range Line Road interchange in Joplin is set for Tuesday, Jan. 17, in Joplin, and the same information will be provided on MoDOT's web site for people to view.

The project will replace the I-44 bridges over Range Line Road and convert Range Line Road (Business Route 71) to a "Diverging Diamond Interchange" underneath I-44.

The in-person and online public meetings are being put on by the Missouri Department of Transportation, with animations and drawings explaining the project:

* The in-person meeting will be 5 p.m. to 7 p.m. in MoDOT's Joplin Regional Office, 2915 S. Doughboy Drive north of 32nd Street.

Visitors may come and go at any time during the open-house meeting and talk with engineers about the design of the project. No formal presentation is scheduled.

Parking is in front of MoDOT's Regional Office. That's north of the Joplin School District's administration building (the former MoDOT district office).

* The online meeting can be found at modot.org/southwest between Jan. 17 and Jan. 31.

The same animations and drawings presented at the in-person meeting will be published on line to view.

Comments may be submitted electronically. Questions emailed to MoDOT will be answered by one of the engineers involved in the project.

Comments will be taken until 5 p.m. Tuesday, Jan. 31.

The Project

Reconstruction of the interchange, at Exit 8, is expected to begin in the late summer or early fall of 2012 and be completed by the end of 2013.

The estimated $9-million project will involve:

* Replacing the two I-44 bridges over Range Line Road (Bus. Route 71).

A new bridge to carry all lanes of I-44 traffic will be built a bit higher in the air over Range Line Road, providing a clearance of 17 feet underneath I-44. (Clearance currently is 14 feet, 6 inches.)

The new bridge will have two concrete walls dividing the I-44 eastbound and westbound lanes.

The existing bridges, built in 1960 as the interstate was developed, have decks in deteriorating condition. The cloverleaf design, which incorporates the existing bridges, is no longer adequate for today's traffic volumes.

* Converting Range Line Road underneath I-44 into a Diverging Diamond Interchange.

That means traffic in each direction will be shifted to the left-hand side of Range Line Road at traffic signals on either side of I-44. This will enable drivers on Range Line Road to make left turns onto the I-44 on-ramps without having to turn in front of oncoming traffic.

A significant number of vehicles on Range Line Road turn left onto I-44.

* Replacing the existing cloverleaf ramps with directional ramps in a diamond-shaped configuration.

This will eliminate a conflict point on I-44 where cars are slowing down to exit onto Range Line Road and other cars are entering I-44 and looking to merge into high-speed traffic.

* Building dual right-turn lanes from the westbound I-44 off-ramp to northbound Range Line Road.

* Building dual left-turn lanes from the eastbound I-44 off-ramp to northbound Range Line Road.

* Installing new traffic signals on Range Line Road at the ramps and resurfacing Range Line Road through the interchange.

* Building a sidewalk along Range Line Road through the interchange.

The sidewalk will be built between the concrete walls dividing the northbound and southbound lanes of Range Line Road as part of the Diverging Diamond Interchange design.

Traffic Impacts During Construction

Lanes on I-44 and on Range Line Road will be closed at times during construction, but most lane closings will occur at night -- between 7 p.m. and 7 a.m.

Short-term ramp closings will be needed at times.

Range Line Road may have to be closed for two or three days toward the end of the project to complete the conversion to a Diverging Diamond Interchange.

However, throughout most of the project, all lanes of I-44 and Range Line Road will remain open during daytime hours when trafffic is heaviest.

Diverging Diamond Interchange Design

MoDOT sees the Diverging Diamond Interchange as a good solution to improve traffic flow and safety on Range Line Road at I-44.

Under the Diverging Diamond Interchange design, the opposing lanes of Range Line Road will criss-cross at traffic signals on either side of I-44. Crossing over and traveling underneath I-44, the oncoming traffic on Range Line Road will be on the right. Opposing lanes will be divided by concrete barriers, with a pedestrian walkway in between the walls.

The configuration will provide left-turning vehicles on Range Line Road a "free left" onto I-44. At the same time, traffic continuing north or south on Range Line Road will be able to travel through the interchange without being stopped due to a back up of left-turning traffic. That means less congestion.

Signs, pavement markings and concrete islands will clearly guide drivers and help prevent wrong turns into the opposing lanes.

Right-angle crashes involving left-turning vehicles from Range Line Road to I-44 should be eliminated and rear-end crashes should be reduced because backups will be less frequent.

Diverging Diamond Interchanges Elsewhere

Five Diverging Diamond Interchanges already are in use in Missouri:

* Two in Springfield -- at Kansas Expressway (Route 13) and I-44 on the north side of Springfield, opened in 2009, and at National Avenue and James River Freeway (Route 60) on the south side of Springfield, opened in 2010.

* One at Route 248 and Route 65 in Branson, opened in 2011.

* One at Dorsett Road and I-270 in St. Louis.

* One at Front Street and I-435 in Kansas City.

More Diverging Diamond Interchanges are being designed or built in Missouri and in many other states.

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