Happy holidays!

2011 is quickly wrapping up and what a year it has been!

Here at the ADOT Blog, we’ve enjoyed being able to showcase some of the interesting and exciting things that have happened at the Arizona Department of Transportation this year.

We’ll keep on posting in 2012 but the blog is going on a break for the rest of 2011. We’re going to be back the first week of the new year armed with fresh topics, fun facts and some more of those great videos! 

But before the holiday hiatus, there are a few things we want to let you know about …

• It’s just the blog that’s taking a week-long vacation! All ADOT and MVD offices will be open EXCEPT for Monday, Dec. 26 and Monday, Jan. 2 when they’ll close in recognition of the Christmas and New Year holidays.  
• There are plenty of places to find ADOT information online. Be sure to check out the ADOT Twitter feed and Facebook page. If you’re looking for detailed traffic conditions head over to az511.gov.
• Some good news for anyone with Arizona holiday travel plans. There will be NO state highway construction closures over Christmas and New Year’s weekends! Although no major restrictions are scheduled, drivers should be prepared for existing work zones and for some ongoing projects and possible increased traffic before and at the end of each holiday weekend over the next two weeks. You can find a complete list of ADOT’s existing work zone locations on the ADOT site.

We hope you all stay safe and have a very happy holiday season … and, if you happen to be looking for some winter reading material you can always scroll through our blog archives!

SR 143 construction surpasses half-way mark

Crews work on the new ramp connecting westbound Sky Harbor
Boulevard to SR 143. Construction is nearly finished and the ramp
is anticipated to open in early 2012.

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.

Attenuators designed to take the impact of vehicle collisions

An example of a fixed attenuator that has been hit.

Back in July we told you all about truck-mounted attenuators and how vital they are to the safety of ADOT employees and drivers out on the road. 

But, there’s another type of attenuator that acts on the same principle and does just as much to protect motorists...

Instead of being attached to a truck, fixed attenuators are placed at the end of barrier walls on the freeway. You’ll see them near off-ramps or medians and anywhere a barrier wall comes to an end.

Like truck-mounted attenuators, fixed attenuators will take the impact of a vehicle collision and absorb a lot of the energy from a crash.

This is by no means a physics blog, but a basic grasp of how energy works is needed to understand attenuators …

A vehicle’s speed and size determine how much energy it has. Normally, this energy is dissipated by your brakes, which burn off that energy slowly, allowing you to come to a safe stop.

But, if a vehicle stops by crashing into a wall, the energy is dispersed very suddenly, resulting in a car that’s crushed. Attenuators won't exactly give a soft landing, but they do work to dissipate the energy slowly like your brakes do. Various attenuators do this by different methods.

There are a few different types of fixed attenuators; however most of them will look pretty similar to drivers.

Quiet Pavement Pilot Program

Back in the early 2000s ADOT started to hear from drivers who said certain stretches of Valley freeways seemed quieter than others.

ADOT and the Maricopa Association of Governments (MAG) noticed a difference, too.

It seemed that areas paved with an asphalt rubber friction course (rubberized asphalt), which MAG funded through the Regional Transportation Plan, were less noisy than freeway surfaces with cement concrete pavement.

ADOT set out to determine whether the rubberized asphalt really did make any difference when it comes to noise abatement. ADOT officials also wanted to know whether the perceived noise-reducing properties of the rubberized asphalt would last as the pavement aged.

New 303/Greenway construction bypass built in 43 hours

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!

ADOT utilizes GIS to manage information, analyze and plan

An example of a map available on ADOT's site.

The saying, “a photo speaks 1,000 words” holds true when it comes to data.

Because, for most people (we’re not talking about the engineers who are out there reading this!) it’s hard to pull real meaning from just a long list of numbers.

But, when you feed those numbers and information into map (it’s sort of like a photo, right?), you start to find relationships between the data.

At least, that’s the super-simplified idea behind Geographic Information Systems, a.k.a. GIS, which ADOT uses to plan, analyze, model and manage information.

ADOT’s GIS Section Manager James Meyer explains GIS as being similar to a database, but because it has a spatial element – meaning you can plot several layers worth of data onto a map – GIS is very valuable in reaching conclusions and making decisions.

For instance, ADOT could plot traffic count data onto a map along with another layer that gives pavement condition scores. From there, it would be easy to “see” where and how traffic affects the road conditions, leading to planning and funding choices.

Some of the ways ADOT utilizes GIS …

Loop 303/Greenway intersection closure slated for this weekend

Click on map for larger view.

Crews are going to move a lot of dirt as they widen Loop 303 in the West Valley. But, at one intersection, there’s a crucial bit of work that needs to get done before they can start digging!

This weekend the Loop 303/Greenway Road intersection in Surprise will be closed beginning 10 p.m. Friday so crews can quickly re-align the intersection, install a temporary traffic signal and temporary sidewalk.

Access to homes and businesses in the area will be maintained (see map for detours) and the “new” intersection will be open in time for Monday morning commutes.

The re-aligned intersection will be in place for about 10 months and is necessary so crews can work to build a Greenway Road overpass that eventually will take traffic over the improved section of Loop 303.

Winter weather suspends northern projects for the season

Snowy conditions from up north earlier this year.

The official start of winter is approaching, but the cold weather is already here!

Over the past few weeks, we’ve told you how ADOT prepares for the snowy conditions common this time of year in Arizona’s high country.

Getting the snowplows and plenty of deicer ready, along with closing down certain low-traffic/heavy snow routes are vital steps, but there’s an additional action ADOT takes each year as the temperatures start to dip …

Every winter ADOT has to suspend work on projects in the state’s high country. This is necessary because it is too cold to pour concrete or place asphalt pavement (rubberized asphalt is especially sensitive to temperature variations).

But that doesn’t mean our crews just drop what they’re doing!

Building a Freeway: Moving Dirt

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.

State Transportation Board 101

ADOT’s Long-Range Transportation Plan was formally adopted earlier this month.

(You might remember that we blogged about the plan, right here, and wrote about the successful outreach effort used to help shape the plan, here).

ADOT planners will now use the Long-Range Transportation Plan as a guide to build a transportation system designed to carry Arizona into the future!

But just who is this group – otherwise known as the State Transportation Board – that adopted the plan?

The State Transportation Board is made up of seven members appointed by the Governor. Six of the members are chosen to represent a specific transportation district and one serves at large. Board members serve a term of six years each.

In addition to serving in an advisory capacity to the ADOT Director, the Transportation Board is granted specific policy powers and duties, including:

• Responsibility for establishing a complete system of state highway routes and determining which state highway routes are accepted into the state highway system and which state highway routes are to be improved.
• Final authority on establishing, opening, relocating, altering, vacating, or abandoning any portion of a state route or state highway, including establishment of parkways and historic and scenic roadways.
• Awarding construction contracts and monitoring the status of construction projects.

And it doesn’t end with roads…