With roughly 240,000 vehicles driving through it each day, the I-10 Deck Park Tunnel needs the night off every once in a while for a good, thorough scrub!

Just about every four months, the tunnel is closed to traffic in order to allow crews the chance to wash the walls, maintain the ventilation systems and check on the tunnel’s 3,700 light fixtures (about 150-200 light bulbs are changed out each quarter!).

Crews typically complete the cleaning over two nights. That means only one side of the tunnel needs to be closed each night … leaving the other direction open to traffic.

Cleaning the white tile walls not only gives the tunnel a fresh look, but it also helps brighten things up a bit.

“We’re washing the walls and keeping them clean so the light bounces off the wall onto the deck so it makes a better drive through,” says ADOT Highway Operations Supervisor Ed Walsh in the video above.

A little history …

For anyone fairly new to the Valley, it might be hard to believe that the Deck Park Tunnel represents part of Interstate-10’s “final mile.”

It was 21 years ago this month that the tunnel was completed, closing up the last remaining gap in the 2,460-mile-long interstate that stretches across the country.

The project was a big one because the path of this final mile was in between two historic Phoenix neighborhoods.

Designers came up with an innovative plan to limit the impacts on the communities. Builders dug out the freeway’s path, put in the 10-lane roadway and covered up the top of the road with a deck made out of 19 side-by-side bridges, created a tunnel and then built a 30-acre city park on top. The project took more than five years to finish and cost an estimated $700 million.

The new Mescal Road/J-Six interchange is taking shape!

The Cochise County bridge will soon reunite two communities that were unexpectedly disconnected after trucks collided beneath the old overpass in March.

After a fast-paced pre-construction process, work to rebuild the bridge began in early July. Just one month in, the hard-working crews from Vastco Inc. have constructed the bridge columns next to the eastbound lanes and erected shoring on those new columns to pour a new pier cap, and completed the pier caps atop the other columns that survived the fiery crash.

All this is in preparation for the setting of 35 new bridge girders, which are scheduled to make their appearance on the scene later this month!

Rebar that will tie into a new pier cap pokes skyward from four new columns next to the eastbound lanes of I-10 at the project to replace the overpass.

Folks driving past this project on I-10 can expect two overnight closures – with traffic exiting on one side of the project and re-entering the interstate on the other side – while those girders are put into place.

Before you know it, a new bridge will mark the return of the short drive residents of Mescal and J-Six Ranch have missed these past several months.

ADOT truly appreciates the support and patience of these communities and looks forward to celebrating the reopening of the Mescal-J-Six bridge this fall!

Talk about a quick turnaround … it’s been just three months since a fiery crash destroyed the Mescal Road/J-Six Ranch Road bridge in Cochise County and already ADOT has approved a contract to rebuild and reopen the bridge this fall.

Considering the process can normally take up to two years, it is clear this project is critical to the nearby communities.

You might remember that the bridge suffered heavy damage back on March 15 after two semi-trucks collided underneath it. The damage from the resulting fire was so severe that the bridge was demolished by ADOT a few weeks later on April 8.

But, with the bridge gone, so is the link between the communities of Mescal and J-Six Ranch, and that is why the replacement project is on a fast track.

In fact, construction is expected to begin early next month at the site located on I-10 at milepost 297, west of Benson.

The project includes replacement of four columns, retrofit of abutments, installation of new precast concrete girders, construction of the concrete roadway, placement of approach slabs, painting of the existing and new portion of the bridge, pavement marking and other related work.

Federal Highway Administration emergency relief funds, a shortened time frame for designing the replacement bridge and a quick construction bid process all have helped move the project ahead at a rapid pace.

Drivers in the area should know that detours have been in place since March 15, when fire damage to the concrete piers and steel girders required closure of the bridge, which was originally built in 1958. The adjacent pedestrian bridge was not damaged by the fire.

The bridges over Pinewood Boulevard in Munds Park have been carrying Interstate-17 traffic for the past 53 years and now it’s time for some well-deserved reconstruction!

ADOT has already begun the project that will rebuild the bridges and ramps on I-17 at Munds Park, an area just south of Flagstaff . Work started last month and is scheduled to wrap up by fall 2012.

When the job is finished, motorists will have two new bridges each measuring 100-feet long (they’re now just 25 feet). The bridges will also be wider to accommodate an eventual third lane planned for I-17. A new sidewalk on Pinewood Boulevard is going in, too. It will allow pedestrians to cross safely underneath I-17 (see above video).

This update is necessary because there is more traffic now then when the bridges were built in 1958. Back then there was no development in Munds Park . The bridges are just inadequate for today’s traffic.

Drivers should expect some slowing of traffic due to this project – especially over busy holiday weekends. It is expected that delays at peak holiday travel times could reach up to 45 minutes … so please plan accordingly.

Project Timeline

April 2011 - Oct. 2011: The northbound bridge will be demolished, then reconstructed and I-17 will be repaved through the work zone. Because the northbound bridge is closed, motorists traveling northbound on I-17 will be directed to a detour that crosses over the median and utilizes southbound lanes. All on and off ramps will remain open.

April 2012 - Oct. 2012: The southbound bridge will be demolished, then reconstructed and I-17 will be repaved through the work zone. While this work is being done, the southbound bridge will be closed and motorists will be detoured over to the northbound lanes of I-17.

In just 10 hours this past weekend, two bridges in southern Arizona were demolished in order to make way for something new.

All it took was some good planning, plenty of patience from motorists, a few enormous machines, and a ton of work by crews on the sites.

A little bit of background …

In November of 2009, ADOT began work on the I-10 Marsh Station Traffic Interchange in Southern Arizona -- a $10 million American Recovery and Reinvestment Act project that includes the extension of Marsh Station Road, drainage improvements, and the construction of a new traffic interchange to accommodate commercial truck traffic.

As it stood, the old Marsh Station Bridge had a clearance of 15 feet -- too low for most commercial trucks to clear. To avoid the bridge, trucks taller than 15 feet have had to maneuver a winding, two-lane, 67-mile detour.

(Note: Not until a nearby Union Pacific Railroad bridge is removed later this year, will most trucks be free to ditch the detour and safely pass through the new traffic interchange.)

But first things first, the old Marsh Station Bridge needed to come down. The only way to secure the work site and ensure the safety of both ADOT crews and the travelling public, however, was to close Interstate-10...forcing all local and interstate traffic into that same 67-mile detour!

After a lot of planning -- being careful to avoid Spring Breaks and other heavy-travel holidays -- ADOT set a date (April 8) and made arrangements to bring down the bridge, clean up the debris, and reopen the interstate, all in a 10-hour, overnight window.

The unexpected...

About three weeks before the demolition was set to occur, on March 15, two semi trucks collided under the overpass at the Mescal Road/J-Six Ranch Road Bridge about eight miles down the road from the from the old Marsh Station Bridge. The bridge was badly damaged from the resulting fire and would have to be replaced.

The task...

Since the interstate was already going to be closed, was it possible to safely get another bridge down in the same 10-hour window? Sure it was, and here’s what it took…

Breakdown by the numbers:

250:
The approximate number of tons of dirt that went down on the roadway below the bridges to act as a cushion for what the crews tore down.

1,480,000:
The approximate number of pounds of concrete removed during the demolition of both bridges. If you need a way to visualize just how much heft 740 tons is, it’s equal to the weight of about 120 adult male African elephants.

112,000 and 232,000:
The approximate pounds of rebar (112,000) and steel (232,000) that were removed during the take down of both bridges.

6:
The number of excavators used on both projects. Two excavators with scissor-like attachments worked on the Marsh Station Bridge demolition. Four excavators (two with the scissor-like attachments and two with hydraulic hammers) worked to bring down the Mescal Road Bridge.

45:
The number of seconds it takes us to show the Marsh Station demolition in this time-lapse video!