If you’ve driven the Loop 303 recently, you know that construction is now in full swing from I-10 all the way up to Mountain View Boulevard near US 60 (Grand Avenue)…

Crews are working to turn what was a two-lane roadway into a modern freeway (three lanes in each direction).

While the entire corridor won’t be finished until 2014, there is a section in Surprise – from Peoria Avenue to Mountain View Boulevard – that is nearly 90 percent complete. That means by around mid-July, drivers in the West Valley will notice a big difference along this six-mile stretch!

Not only will there be three lanes in each direction, but the project also includes a median, auxiliary lanes and signalized traffic interchanges at Bell, Greenway, Waddell and Cactus Roads.

The freeway will be essentially finished (along the Peoria Avenue to Mountain View Boulevard portion only), but crews will need to come back in the fall to place rubberized asphalt.

On the project site Right now, crews have paved most of the southbound lanes. You might remember that the northbound side was completed first (north- and southbound traffic now travels along a portion of the improved northbound lanes).

Retaining walls and the sound walls are up, too.

Crews continue to work on curb and gutters, lights, fencing, and cable barriers. They’ll also be stabilizing the slopes on the project with seeding and wattles. On the heels of this section’s completion, a landscaping project will start up to spruce up the freeway-facing areas.

Drivers will also notice that the portable batch plant will soon be moved from its current spot at Greenway Road to a location further south, so that it may be used for other portions of the Loop 303.

Drivers might also have observed two piles of dirt near the Grand Avenue and Loop 303 intersection. That is dirt that’s been excavated as a part of this project. It will be recycled and used once work starts on the 303/Grand Avenue traffic interchange.

The improvements to SR 143 are really coming along...

In fact, construction now is about 64 percent complete!

Another highlight to point out is that there are no restrictions or closures planned for this project through the beginning of the new year. That’s important to know during this busy holiday travel season because SR 143 (also known as the Hohokam Expressway) provides many drivers access to Phoenix Sky Harbor International Airport.

About the project

As we told you back in July this project includes the addition of two new ramps that are being constructed on the SR 143 to help commuters get directly in and out of the airport.

A third ramp will connect motorists traveling on westbound Sky Harbor Boulevard directly onto southbound SR 143, which will ease congestion at the intersection of Sky Harbor Boulevard and SR 143 by allowing drivers to bypass the intersection and gain quicker access to I-10.

There’s also an existing ramp on the east side of SR 143 that is being reconstructed along with signage improvements and landscape work.

A few construction milestones ... so far

• Just last week, crews started widening southbound SR 143 at the Salt River Bridge. When complete, this area of freeway will be expanded from three to four lanes in order to handle the traffic merging from the new west and east ramps.
• Crews used 50,000 cubic yards of dirt (yes, we’re talking about dirt again!) to form an embankment that will support the new ramp connecting eastbound Sky Harbor Boulevard directly onto southbound SR 143.
• The ramp connecting westbound Sky Harbor Boulevard with southbound SR 143 is nearly complete (see photo above) and should open to motorists by early 2012 while other construction improvements continue to be made on the rest of the project.

When construction on the entire project is complete in summer 2012, drivers are going to have improved access to and from the airport and they’ll experience better traffic flow on SR 143.

Accommodating existing traffic is a key priority when ADOT builds a freeway …

Depending on the project, that can mean working out a construction schedule that takes rush hours into account or hiring extra crews to flag and direct traffic through the site.

But, on the Loop 303 project in the West Valley drivers will notice a new construction bypass that (amazingly) was built in around 43 hours this past weekend. The bypass will be in place for the next 10 months and not only will it allow for a more efficient way to haul dirt, but it’s also going to help drivers avoid the construction zone!

Building the bypass

Crews shut down the intersection at Greenway Road and the Loop 303 at 10 p.m. Friday, Dec. 9.

Roughly 8,000 cubic yards of dirt was hauled in from other parts of the project site to build up the road. That dirt was placed Friday night in eight-inch layers and was compacted until it was the right height for the bypass (see video above!). After that, the road was paved and striped on Saturday.

Prior to the weekend work, crews had built everything they could up until the point where the bypass would cross “live” traffic and require the closure. That required even more dirt – about 40,000 cubic yards.

Crews not only had to build the bypass, but also installed temporary concrete barriers, fencing, sidewalk and a traffic signal.

The traffic signal went in Saturday morning after the power was shut off to the “old” signal. The signal pole’s electric meter and pedestal were set to the new location and power was turned on. ADOT wired the signal Sunday morning and installed a common video detection device that will help with signal timing.

After some finishing touches, the bypass was ready and opened to traffic by about 5:15 Sunday evening – 12 hours ahead of schedule!

Before you can build a freeway, you’ve got to move a little dirt...

Make that a LOT of dirt, especially in the case of the Loop 303 project under construction right now in the West Valley.

Crews are working to construct additional lanes and plan to move about 3 million cubic yards of dirt by the time the project is finished. (By the way, a lot of work is planned for the Loop 303. The portion of the project we’re talking about runs from Mountain View Boulevard, south to Peoria Avenue.)

That much dirt translates to roughly 200,000 truck loads – and these are some big trucks (take a look at them in action in the video above).

Other projects may, or may not require this much earthwork. It depends on the road design and the original shape of the terrain.

Take the Loop 303 project for example...

Part of the freeway (starting slightly south of Greenway Road headed north) is going to be depressed ... in other words, freeway traffic will pass underneath the nearby local streets. The rest of the freeway (heading south of Greenway down to Cactus Road) is going to be elevated and will pass over local traffic.

So, parts of this project need to be dug out and other portions need to be lifted up. The dirt that crews dig out in some areas helps to build the overpasses in other spots.

If you’re lucky, it all balances out. Otherwise, purchasing additional dirt is an option. Or, if there is a surplus, the extra dirt often can be utilized in landscaping and to build berms.

Moving the dirt...

Before any digging can start, the dirt is pre-wet to make it easier to move and help with compaction and dust control.

After that, there’s some heavy-duty equipment that comes into play.

Typically, an excavator is used to dig up the dirt. The excavators being used on the 303 project have buckets that hold about seven cubic yards worth of material at a time. Those load onto something called a belly dump truck (see photo below).

Scrapers also are used to dig up the dirt. Depending on their size, scrapers can hold and transport about 14-18 cubic yards at a time.

Contractors have geotechnical reports that tell them the type of soil they’re going to be dealing with. Crews sometimes will run into rocky terrain on projects, which requires blasting.

Whether they need to blast or just dig, crews have to put the dirt somewhere...

If it’s being used on the project (as is the case with the Loop 303), the dirt is hauled to where it is needed.

It is dumped in 8-inch lifts (or layers) and is knocked down with a compactor and roller until it reaches the necessary compaction rate – again, this is where pre-wetting the dirt comes in handy.