Tag: Transportation Engineering

New Changes for Designing Low-Volume Roads

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While staying up-to-date on standards, manuals, guidelines, policies, and specifications can be challenging, the Hoyle, Tanner design teams have welcomed the Second Edition Guidelines for Geometric Design of Low-Volume Roads (Guidelines) recently published by the American Association of State Highway and Transportation Officials (AASHTO). The updated guidelines expand the definition of low-volume which provides greater flexibility to Hoyle, Tanner’s engineers to design the appropriate solution for the challenges our clients face. We’re going to cover some basics of the Guidelines and why it is so welcomed.

In the first edition (2001), low-volume roads were considered to have traffic volumes of 400 vehicles per day (vpd) or less. With the newest release (2019), the Guidelines expand coverage to roads with traffic volumes of 2,000 vpd or less. What does 400 vpd look like? For perspective: If you were to walk down a street, you’d expect to see one vehicle approximately every 3 ½ minutes at 400 vpd. If the same road experienced 2,000 vpd, you’d expect to see one vehicle approximately every 45 seconds.

According to the Guidelines, 80% of the roads in the U.S. are low-volume roads.

To determine if that 80% was applicable to our clients, we reviewed available traffic counts for an “average” New Hampshire town and found a conservative 70% of their road miles met the new definition of low-volume.

The Guidelines still remain focused on very low-volume roads (≤ 400 vpd) but the inclusion of roads with volumes of ≤ 2,000 vpd is greeted with open arms. This provides our design teams an additional resource on more projects; before the latest release we could not use the Guidelines on most of our projects as traffic volumes typically exceeded 400 vpd. However, a majority of past projects had traffic volumes that did not exceed 2,000 vpd.

What’s the benefit to our clients and designers

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The Guidelines apply to both new construction and evaluating existing roadways. Here are a few things designers can consider for the construction of a new low-volume road:

Reduce pavement width allocated to vehicles, narrow the road. The obvious benefit to narrower roads is reduced construction cost. Another benefit is a decrease in environmental impacts. Thinking a little bit further beyond the edge of road, the savings from a narrower road could be invested in pedestrian and bicycle accommodations.

Reduce the design speed, allowing for the use of sharper horizontal curves. This could be used to avoid or minimize impacts to environmentally sensitive areas, an excessive cut, an excessive fill, or negative impacts to abutting properties. Doing any of these could not only reduce construction costs, but also potentially speed up the construction time and reduce the environmental permitting coordination.

Reduce the stopping sight distance, allowing for the use of sharper curves. Similar to reducing the design speed, however, this provides the designer flexibility for both the horizontal and vertical (profile) alignments. This could be used to avoid or minimize impacts to environmentally sensitive areas, an excessive cut, an excessive fill, or negative impacts to abutting properties. Doing any of these could not only reduce construction costs, but also potentially speed up the construction time and reduce the environmental permitting coordination.

Reduce the clear zone, and thus reduce or eliminate guardrail. A little side note, a clear zone is an area that allows a driver to stop safely, or regain control of a vehicle that has left the roadway. Since guardrail is a roadside hazard, costly to install, and costly to maintain when impacted, being able to reduce guardrail or eliminate it reduces construction maintenance costs and potential accidents involving it.

With this increased flexibility the Guidelines provide there is still engineering judgement to be used. For instance, it would be ill-advised to combine a narrow road with sharper curves and reduced stopping sight distance. Remember the intent of the Guideline is to reduce crash frequency and severity while prudently using public funds.

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What about all the existing roads to be maintained?

We have the ability to evaluate how the existing road is performing and if it meets the Guidelines. When something doesn’t meet the Guidelines, that doesn’t mean that it needs to be fixed.

For example, let’s consider a one-mile segment of low-volume rural road in good condition, and we’re looking to resurface it before it becomes worse. We go out to the site, take measurements and notes of existing conditions, and find the following:

  • The average road width is less than the Guideline recommendation.
  • There is a curve that is sharper than the Guidelines minimum radius, has no warning signs, appears multiple vehicles have left the paved surface within the curve but no reported accidents in the last 5 years.
  • There are multiple trees within the clear zone but no signs of impacts or reported accidents.

There are several ways to address each of the issues. Recalling the purpose of the Guidelines is to make improvements at locations where it can be expected to provide substantial crash reduction benefits the design team makes a recommendation. Maintain the existing road width except within the sharp curve, where the pavement is to be widened to the Guideline minimum and the trees within the clear zone are to remain.

Hoyle, Tanner’s transportation design engineers are experts in roadway design, pavement layout, roadway stormwater, and safety for vehicles and pedestrians alike. We research and commit ourselves to learning the newest design guidelines for a safer, healthier community for drivers, roadway designers, and pedestrians. Questions? Call (603) 669-5555 ext. 181 or email me to discuss the latest technology and guidelines in the transportation engineering industry.

4 Things We Learned about Electronic Tolling in New Hampshire

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A few weeks ago, we attended the New Hampshire Institute of Transportation Engineers (NHITE) fall meeting (where I serve as NHITE president). Our engineers learned about the history of tolling in New Hampshire, tolling technology, and details on design and challenges at planned All Electronic Tolling (AET) locations in Dover and Rochester.

Electronic tolls are just what they sound like – overhead scanners that connect to an account like E-ZPass to pay your toll. They replace the manned/unmanned booths (barrier tolls) and the need for rolls of quarters or tokens. They help with alleviating traffic that builds up at toll booths during peak seasons. Just like barrier toll booths, though, they have their challenges. Fee collection systems must be properly designed and monitored to ensure revenue is not lost while driver privacy must be protected.

These are all considerations that engineers and system administrators must consider when thinking about implementing AET.

Key takeaways we want to share

  • Collecting tolls is vital for maintaining turnpike assets in New Hampshire; including nearly 90 miles of limited access highway such as the FE Everett Turnpike.
  • AET tolling increases the capacity of the toll facilities and reduces the congestion felt by drivers. They eliminate vehicle conflict points at merge locations and lane changes, which helps to reduce crashes. AET also reduces environmental impacts with a smaller project footprint and by lowering emissions through reduced acceleration/deceleration.
  • Drivers’ privacy is a primary concern; data that is collected by electronic tolls is erased immediately after all successful transactions.
  • Loss of revenue through “leakage” (travelers who go through the tolls without paying) must be minimized so that funds for road maintenance and repairs are available.

How this will help you

Attending conferences and trainings like these helps Hoyle, Tanner staff keep abreast of the latest technologies and ideas that we can use to better serve our clients.

Heat Safety: 4 Tips to Stay Safe on Construction Sites During Summer

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Summer is officially here, and although the warm weather brings promises of barbecues, beach days and the hum of AC, working in the summer heat is not something to be taken lightly. For construction laborers and other outdoor workers, the heat can drain your energy and be very dangerous if proper precautions aren’t taken.

According to the Bureau of Labor Statistics’ most recent data, in 2015 over 2,830 American workers suffered from a heat-related illness that required at least one day away from work. In order to prevent more injuries now and in the future, it is important to spread awareness in the workplace about how to stay safe while out and in intense summer conditions. By planning ahead and executing these simple safety measures, you will be happier, healthier and ready to enjoy all the fun that the summer heat has to offer.

Drink Water

Staying hydrated is the single most important thing you can do to prevent heat-related injury or illness. The Occupational Safety and Health Administration recommends drinking water every 15 to 20 minutes even if you are not thirsty. Additionally, anyone exposed to prolonged periods of sweating should balance out their electrolytes by drinking sports drinks such as Gatorade or Powerade. Keep in mind, though, that sports drinks are laden with food dye and sugars, so you can also boost your electrolytes by eating mineral-rich foods like bananas, nuts, yogurt, and dark green vegetables like kale. Coconut water is another good source of replenishing electrolytes. If you can’t carry snacks around, some say that adding a pinch of salt and a squeeze of lemon to your water can have a similar satisfying effect.

Be Cautious of Caffeine

Coffee is an essential part of the day for many Americans. However, all caffeine — whether it be coffee, tea or soda — can be dangerous on a hot summer day if you aren’t careful. This is because caffeine can be diuretic, meaning that it causes water loss in the body and dehydrates you more quickly. Whether or not caffeine is actually a diuretic has been debated over the past few years, but your reaction is also very subjective; someone who rarely drinks caffeine may feel its effects more than a daily consumer, especially on a hot day. Drinking water throughout the day should counter these effects, but be wary of drinking excessive amounts of caffeine, especially while on the job site.

Take Breaks

Do not be afraid to take breaks. No job is worth risking your health over. The heat can be draining, and it is important that you allow yourself the time you need to recuperate. When you do take breaks make sure you find some shade, drink at least 20 ounces of water and reapply sunscreen. For lunch, eat healthy and energizing foods. You will be surprised how much stronger you feel throughout the day.

Know the Symptoms

Excessive heat can lead to heat exhaustion and heat stroke. It is important that you are able to recognize these symptoms and know what to do if the situation arises.

Heat Exhaustion

Nausea, vomiting, headaches, weakness, confusion, dizziness, and cool, pale, moist or flushed skin can all be signs of heat exhaustion. If you or someone you know is experiencing any of these symptoms it is important that you immediately move them to a cooler location and start to loosen any tight or heavy clothing they are wearing. You need to lower the person’s body temperature by any means necessary. Some examples of how to do this include fanning them, spraying them down with cool water or resting wet towels on their skin. If the victim is conscious, start replenishing their fluids by having them drink water slowly (about 4 ounces every 15 minutes). Keep a careful eye on the person and watch for any changes in their condition. If they refuse care, begin to lose consciousness or start to vomit, call 911 or local emergency authorities immediately.

Heat Stroke

Signs of heat stroke include hot dry red skin, confusion, loss of consciousness or convulsions and seizures. Heat stroke is an extremely serious condition and can be fatal, so if you witness anybody experiencing any of these symptoms, call 911 immediately. While waiting for help to arrive, cool the person down as quickly as possible. If circumstance allows, immerse the person up to their neck in cold water. If that isn’t an option, spray the person down or apply ice packs or wet towels to their skin.

For more information on what to do when temperatures rise, download the free Red Cross Emergency App. The app also gives users the option to receive alerts for excessive heat watches, warnings and heat advisories.

We want this summer to be memorable for a lot of reasons, but overheating is not one of them. When working outdoors in hot weather, the most important things to remember are water, shade and rest. Anyone can be at risk for severe dehydration and heat exhaustion, but people who are not used to prolonged exposure to heat typically are at a higher risk of suffering an injury. As things start to heat up this summer, ease your way into your work, especially if you are a new employee. Listen to your body and take the necessary precautions to ensure that you are both safe and successful.

Now get out there and enjoy the sunshine!

 

 

Written by Grace Mulleavey

 

 

 

 

Designing Bicycle Box Systems to Keep Cyclists and Motorists Safe

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Everyone knows about bicycles. Like any sport, they have a fandom following, from avid Tour-de-Francers to all those dedicated bike-to-workers. Not to mention, it’s practically a rite of passage to learn how to ride one, and it’s the quintessential comparison when talking about things you never forget how to do once you learn.

Despite their popularity around the world, America still shines with its youthful glow in comparison to many historic countries; we just don’t have the same bicycle-laden streets that other countries have grown to cherish. That’s not to say that America isn’t making strides to enhance its bike-ability. Major cities have hundreds of miles of bike lanes, while New York City tops the list at having 1,000 miles.

Though America has some catching up to do, cities have seen overall betterment in roadway safety when communities define where bicyclists should travel on the roads.

One innovative design that’s gaining traction is the bicycle box. From the NACTO website, “A bike box is a designated area at the head of a traffic lane at a signalized intersection that provides bicyclists with a safe and visible way to get ahead of queuing traffic during the red signal phase.”

Bicycle boxes are innovative because they address many safety concerns at once, such as: increasing visibility of bicyclists, preventing “right-hook” conflicts, provides priority for bicyclists, and groups bicyclists into one obvious area, making it easier for cyclists to clear the area quickly.

Recognizing these benefits, Hoyle, Tanner recently designed a bicycle box system on Farrell Street in South Burlington, Vermont, which will become the first approved installation in the State. As Farrell Street is part of the route of the Champlain Bikeway (a 363-mile scenic loop around the lake), the City is dedicated to improving access and safety in this location and throughout the City. At the Farrell Street/Swift Street intersection, the City was particularly concerned that southbound cyclists looking to make a through or left turn would conflict with vehicles turning right to access US 7 & I-189. A bicycle box was the perfect solution. Hoyle, Tanner worked with the Federal Highway Administration (FHWA) and gained interim approval for the City’s use of this valuable tool, which is required for new traffic control devices that have not yet been formally adopted. Partnering with Howard Stein Hudson, Hoyle, Tanner designed the bicycle boxes which will employ special highly visible green pavement markings and thermal or video bicycle detection to reduce collisions and improve safety at the intersection. With this experience, Hoyle, Tanner will look to aid other municipalities and state agencies with this and other emerging traffic control technologies, with a goal of improving the recreational and commuter transportation experience for all users.

How Your Community Plays a Part in National Walk to Work Day

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Spring has arrived just in time for National Walk to Work Day! Individuals across the country are lacing up their sneakers and hitting the pavement, while communities are taking a more holistic approach to ensuring safe pedestrian and bicycle travel. Many municipalities are introducing the concept of “complete streets”, introduced by the National Complete Streets Coalition, to their design efforts to balance safety and convenience for motorists, transit users, pedestrians and cyclists alike. Currently, there isn’t a single design for a complete street; it represents creating roads that are safe for all users, regardless of age, ability, or transportation method. Growing in popularity, some of the complete streets features are being implemented throughout the state, including:

Traffic Calming
With the growing demand for alternative modes of transportation, traffic calming measures are being introduced on various roadways to ensure safe travel for all users. The use of narrowed throughways, speed bumps/humps/tables,chicanes, and curb extensions (bulbouts) are some of the many features being used in the efforts to slow automobile travel, including the Union Street Reconstruction in Peterborough, New Hampshire. This project also incorporated tree plantings along the medians to beautify the area.

High Visibility Crosswalks
History shows pedestrian crossings existing more than 2000 years ago, where raised blocks on roadways provided a means for pedestrians to cross without having to step on the street itself. In current designs, high visibility crosswalks are incorporated to guide pedestrians and alert motorists to the crossing locations. Six foot wide crosswalks are installed using long lasting plastic/epoxy or paint embedded with reflective glass beads to assist in the crossing markings. In addition to local governments, universities, like the University of New Hampshire, are incorporating these crosswalks on their campuses.

Shared Use Paths
A multi-use path or trail that has been separated from motor vehicle travel and has been established for alternative transportation purposes is another option that is growing in popularity. Utilizing existing right-of-ways to create these travel corridors for pedestrians, cyclists, skaters, equestrians, and other non-motorized users in some instances are also used to observe the natural environment in various communities. Recently, a shared use path was completed connecting Manchester’s and Goffstown’s trail system.

Multi-Modal Intersection
Intersections have the unique responsibility of accommodating and coordinating the nearly-constant occurrence of conflicts between all modes of transportation. Multi-modal intersections focus on intersections where numerous modes of travel come together and the coordination is required for the safety of all users. Utilizing different design features such as corner refuge islands, forward stop bars, and dedicated bike lanes, as used on Manchester Street in Concord, all intersection users can travel simultaneously, safely.

With many communities implementing these design features into roadway geometry, walking to work can be as simple as strapping on your shoes and heading out the door. By walking to work for this nationally recognized day, you will help reduce carbon emissions, get fit, and avoid the traffic jams.