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NOW YOU CAN ASK AN ENGINEER!
This page is designed to allow readers to submit questions about general transportation topics.
Engineers examine a piece of steel used to support a mechanically stabilized earth wall or MSE wall. Never heard of an MSE wall? Ask away!
If you’ve ever wondered what makes asphalt stick to the road, how traffic detection works or what geofoam is, this page is for you.
To ask an engineer, type your question in the comment box below. Your question and an answer from a UDOT engineer will be sent to you by email and may be posted below.
Questions specific to a construction or maintenance project or issues specific to a location (like an intersection, for instance) are best answered through the Contact UDOT page.
Thank you!
Hello,
I was curious what your opinion was on the dust and particles that get emitted while they are putting down the pavement.
is it something we should be worried about?
Usually during pavement installation, dust is not a a big concern. However if an old road needs to be re-build or a road is built from scratch, fugitive dust is a big concern. Construction contractors are required to control dust by spraying water or other means.
I notice cities like Houston use concrete more than places like Utah and NYC. Is there a reason why you would not use concrete roads? Concrete last longer and pavement has to be re applied yearly.
Kevin VanFrank, Engineer for Asphalt Materials at UDOT offers this answer:
This is a question for the ages and subject to much debate. There are many factors to consider, among them is life cycle cost.
The design life cycle for asphalt pavements is typically 20 years with a maintenance application each 3 years. These treatments may involve surface rejuvenation (sealants etc), skid rejuvenation (chips, microseal, ogsc, etc), or partial depth structural rehabilitation. Although these treatments are relatively inexpensive and rapid, they remain somewhat disruptive to the user.
The design life cycle for concrete pavements is normally 50 years with load transfer, panel replacement and surfacing maintenance done about every 20 years. These activities are slow, expensive and quite disruptive.
Utah regularly bids these two pavement types against each other. With the current costs, Concrete rarely wins without significant subsidy.
There is generally a great deal of investment required in the underlying layers to make concrete function properly. Placing a high value surface over a poor foundation leads to early failure. These costs make the total structure quite costly. An asphalt surface also requires a good foundation but this system is flexible and can handle movement better.
Concrete roads generally involve curing time which makes construction and repair slow. This results in significant but less frequent disruption to traffic.
Concrete roads tend to be much noisier than asphalt in the irritating frequencies. These sound levels require larger and more complex sound attenuation.
Asphalt is sustainable. More asphalt is recycled than any other construction material.
Sometimes a decision to use concrete is made because the loading is too high to make an asphalt solution practical. This often is the case when paving for high truck volumes or at intersections.
As you can see, the decision is not an easy one. It involves load, life cycle, environment, user delay, product availability, and many other considerations.
Who decides what on-ramps need revamping? The I-80/I-215 Foothill merge is AWFUL! How do we get the ‘vote’ out there to spend money on that instead of repairing roads that are could wait a year or two?
Your question is complicated because it involves separate planning processes and funding sources. When it comes to road up-keep, Maintenance funding, (money to fix existing roads) is separate from projects that pay for new roads or big changes to existing roads. Planning for maintenance projects is separate too; engineers measure the quality of the road and determine which roads need a maintenance treatment – like a new coat of asphalt.
Construction projects are planned years in advance. Major changes to freeway ramps require approval from the federal government and compliance with the National Environmental Protection Agency. Although it can sometimes be a long process, getting approval on a freeway project that potentially impacts the flow of traffic is a major change, and a careful planning process before hand is very important. A ramp project like you mentioned may be less involved, however. UDOT works closely with the Federal Highways Administration so determination can be made about how best to comply with federal requirements.
To best make use of state funds, UDOT is careful to prioritize maintenance projects and construction projects. Several factors determine when UDOT decides to take on a major project. A ramp project, for example, may be put off until it can be combined with other work. Safety issues are always handled right away.
What many people don’t realize is that maintaining good roads costs less in the long run. When roads become too damaged, they lose strength and have to be rebuilt. Keeping roads in good condition extends their usable life and is a better use of resources and funding.
Here are some links to more information:
http://www.wfrc.org/cms/index.php
http://www.udot.utah.gov/main/f?p=100:pg:0:::1:T,V:39,
Whatever are the bumps on I-15 & what is the purpose?
I believe what you are seeing are bumps from a project to extend the life of the concrete pavement. Crews are installing load-transfer bars between concrete panels. The bars are placed in cuts in the pavement in the tire path. While the area may be bumpy now, the pavement will be made smooth after installation of the bars. Read a blog post about the project here: http://blog.udot.utah.gov/2011/07/udots-fix-for-aging-concrete-freeways/
How long typically are yellow lights sychronized for before turning red? Who do we report if one is on for 10 seconds whereas a mile away that light is on for 6 seconds?
deal
Where is the I- 15?
There is a good article about I-15 in Wikipedia. The article summarizes where the important interstate highway crosses through each state, along with maps.
If the asphalt mixture that uses oil sands can begin production and implementation how much economic impact would that pose?
@Dusty: Signal synchronization really is location dependent. If you give me the location of the intersection, I will look into the timing and give you a number to call if you’d like to make more inquiries.
@Johnathan Arriola: We have no way of knowing about economic impact at this point in time.
how can I apply to be part of the Incident Management Team?
Contact UDOT Region Two at 801-975-4000 to speak to an IMT worker about the requirements of the job. Then, watch the state employment website to see if a job becomes available.