March 13, 2023
By Sean Delmore, Director of Traffic, WSB

Traffic signals are an often-overlooked aspect of everyday life. But when you stop at a traffic signal, did you ever also stop and think about how, where, and why these signals are used? Here are six things you may not know about traffic signals.  

When is a traffic signal needed?

Communities thoughtfully decide where traffic signals are needed vs. roundabouts or stop signs. An Intersection Control Evaluation (ICE) is conducted to determine the appropriate method of traffic control, which includes a detailed signal warrant analysis. These studies measure the existing vehicular and non-motorized (pedestrian/bicycle) traffic volumes and evaluate crash history at the intersection. WSB traffic experts conduct these evaluations in partnership with communities and local governments to collect the necessary data and determine if a signal would help improve the traffic safety and operations of the area. 

Traffic signals are typically designed to last more than 20 years with routine maintenance and designed to handle forecasted traffic volumes 20 years out. The federal government has requirements that must be followed when planning for the installation of new signals. These requirements include signal warrants that are found in the Manual on Uniform Traffic Control Devices (MUTCD). 

What are the benefits of a traffic signal?

Efficiency and safety are the top benefits of traffic signals. Signals are designed to keep up the progression of heavy traffic while ensuring there are no undue delays to side streets. The signals imitate elements of human decision-making, such as when a pedestrian should cross a busy intersection or when it is safe for a vehicle to make a left turn. Removing that decision from the person and incorporating it into an automated system like the traffic signal increases the overall safety for vehicles and pedestrians.

The ability to efficiently manage traffic flow can also be a significant factor in the success of local businesses and the livability of an area for families. For instance, access management developed by signals reduces the chaos of vehicles entering and existing businesses onto the main corridor.

How do traffic signals communicate with emergency vehicles? 

Traffic signals can change to the green phase for emergency vehicles allowing them to respond quickly and safely to incidents. Most emergency vehicles have an emitter on the dashboard that communicates with the traffic signal to safely end an opposing signal phase and bring up a green indication for the emergency vehicle. The technology also will extend the length of a green cycle if it is currently green for the direction an emergency vehicle is travelling.

Why do traffic signals always turn red for me?

Despite what we sometimes think, not all traffic signals turn red as you approach— in fact, it is just the opposite. Traffic signals have “dilemma zone protection,” which extends the length of a green light when a vehicle passes the back detection as it approaches the light. This keeps the light green to eliminate the human dilemma of whether to speed up or stop when the light turns yellow. 

Additionally, sensors in the ground at the intersection detect cars as they approach. For example, in many signalized locations, a minor street with lower vehicle volumes won’t change to green unless a vehicle is waiting at the red light to maximize the efficiency of the major roadway. 

What’s the latest innovation with traffic signals?

Flashing yellow arrows are one of the latest innovations in traffic signals. The flashing yellow arrow allows the driver to decide when it is appropriate to turn left, as opposed to controlling left-turns with green and red arrows. This feature on signals may also change based on the time of day. For example, the flashing yellow left turn arrow may be used on a Sunday night when traffic volumes are significantly lower. Then, during Monday morning rush hour, when traffic volumes increase substantially, the flashing yellow arrow will not be utilized, and the signal can offer a protected only phase because there is too great a risk posed to left turning vehicles trying to find an acceptable gap against the amount of oncoming traffic.  

What’s on the horizon for traffic signals?

One element of future traffic signals being considered more and more in major metropolitan areas is incorporating pedestrians and cyclists into the signal system. Engineers are rethinking classic intersection designs to incorporate new technology such as Audible Pedestrian Signals (APS) & ADA compliant curb ramp improvements, as well as bicycle markings for improving safety and accessibility for all modes.

How WSB Can Help

If you have concerns or complaints about an intersection, WSB’s team of experts are here to help. We can perform an Intersection Control Evaluation or provide suggestions how to move traffic safely and efficiently through your community.

January 12, 2023

Rob Bailey is the Vice President of Transportation – Texas at WSB. Rob has over three decades of engineering experience. His dedicated background and ability to lead has contributed to the expansion of WSB’s footprint in Texas since joining our firm a year ago.

In this Q&A, Rob shares his reflections on the expansion and future of WSB in the Texas market.

You’ve worked in the Architecture, Engineering and Construction (AEC) Industry for many years, how has your experience informed how you approach your role at WSB?

My experience is almost entirely in the state of Texas, I have over 30 years of experience working on transportation infrastructure, the first ten at the Texas Department of Transportation (TxDOT) which has been foundational for me. Building that foundation has helped me learn about our client needs, understand their culture, and it has allowed me to build personal connections and relationships that I have taken with me throughout my career. Having that background has given me what I need to be successful in this role in terms of leadership and transportation knowledge.

What is your favorite part about leading the Texas transportation team?

I really enjoy the people side of leading. I see my role and team much like a sports team. I am the general manager, and I must understand the rules of the game, and the playing field, and I must analyze and put together a strategy for success. I am also in charge of recruiting the best talent and having the right players. I need to figure out their strengths and weaknesses and find what position fits best within the team and the organization.

How has transportation been advancing in Texas?

The transportation program has changed dramatically over the last year. I am really excited about the team we have built and the clients we have added. Moving forward, we have all the pieces we want in place, and I am really optimistic about the future. Fortunately, the market lines up with my optimism. TxDOT has a steady stream of revenue that will support infrastructure across the state. We are experiencing significant population growth that is stretching city and county resources, which means we need to help build the infrastructure to support that growth.

How has WSB grown? What factors do you think made this possible?

There are two factors that pertain to the growth of WSB. One is the market, along with the policies that elected officials enact. The other is the soft side, the people side. We are focused on our staff. We are committed to hiring staff that is well-known in the industry and well-respected by our clients which will help us to maintain relationships and foster new opportunities.

Why is the Texas market important to the growth of WSB?

The opportunities for growth in Texas are significant. The population and growth of the state are driving both the infrastructure and energy markets. As a company, our mission is to build what’s next in infrastructure and this is a great place to do just that. Our company roots in Minnesota and the deep bench of expertise we have throughout the country help position us for success. The infrastructure needs across our country vary and it helps us expand our knowledge and bring new ideas and innovations to our clients regardless of location.

What makes WSB best suited to support industry efforts in Texas?

WSB has a true understanding of the client’s needs. We believe in working with our clients to help them be successful. Many WSB staff in Texas have experience working for owners, contractors, and engineering firms. These experiences help us understand the challenges of our clients, the real purpose of delivering infrastructure projects, and an overall deep understanding of how to support industry needs.

I am really excited about the team we have built and the clients we have added. Moving forward, we have all the pieces we want in place, and I am really optimistic about the future.

Rob Bailey

What does WSB look like to you in the future?

There has been significant growth for the company, and I don’t see it slowing down. I see it accelerating more each day. It’s a big reason why I came to WSB. I was excited about the opportunity it would bring not only to myself but the staff as well. Our staff will continue to grow, and I am excited to see how everyone will fit into a larger organization. There will be a lot more opportunities and the company will be led by a lot of the younger leaders we have today.

Any advice for leaders now and for those who come after you?

Leadership is a lot like relationships and marriage. Always make sure to pick your battles wisely. Try hard to have a long-term vision with your decisions and actions. One thing that can be challenging in a large company is short-termism. Focused on the next quarter’s reports, and impacts today, and less focused on the long-term. I am impressed with WSB and our long-term vision and investments in staff and technology.

By Do Nam, Director of Traffic Modeling and Technology, WSB

The number of U.S. traffic deaths has been steadily increasing. According to the National Highway Traffic Safety Administration, vehicle fatality rates increased by 10.5 percent up to 42,915 last year, making it the highest number killed on U.S. roads in a single year since 2005.

The use of traffic modeling combined with cutting edge technology to mitigating risk, reducing traffic accidents, better protecting motorists and pedestrians, and analyzing ways to reverse the deadly trend of motor vehicle crashes. 

Trends, Statistics & Human Factors

Reports over the past two years have shown a significant increase in traffic fatalities across the nation. Much of this is attributed human factors like increased risk taking, which appears to have become more common in response to the pandemic.  

In 2020, when COVID-19 hit, the average vehicle miles traveled (VMT) decreased because much of the population was working from home and going out less. However, nationwide fatalities still increased from 36,355 in 2019 to 38,824 in 2020, and then up to 42,195 in 2021. With less traffic on the roads, many drivers were driving faster than the posted speed limit leading to more high-speed crashes. Furthermore, pedestrian, bicyclist, and motorcyclist fatalities were the highest they had been since 1989, 1987, and 1975 respectively.

The number of alcohol-related crashes also increased, which could be attributed to people consuming more alcohol to manage the social and economic stress brought on by the pandemic. 

Improved vehicle designs, seat belts, air bags, and new technologies like blind spot warning and automatic emergency braking systems have contributed to reduced vehicle fatalities over time, but cell phones and other distractions have caused those trends to reverse over the past decade. 

How Artificial Intelligence Improves Traffic Safety 

New emerging artificial intelligence (AI) programs assist engineers in collecting data, mapping out problematic traffic patterns, and predicting the likelihood of crashes. By using drones and traffic cameras to capture data from video, engineers use AI technology to track the movement of individual vehicles, bikes, motorcycles, and even pedestrians.

AI also allows us to better analyze traffic flow, determining work zone movements, space gaps between vehicles, and movements of heavy semi-trucks. Such advanced technology makes our analysis more informed and accurate. Through the use of data, we improve the flow of traffic, increase safety measures for drivers and construction workers, and predict where infrastructure changes are needed for more efficient and safer roads.

By DJ Sosa, Sr Project Manager, WSB

When winter storms sweep across the nation, dangerous road conditions can cause crashes, pileups, and leave commuters stranded for hours on end. How can road design play a role in making roads safer in the winter?

When roads are designed, many elements, such as drainage and flooding, are considered. Unfortunately, snowdrift prevention is often overlooked until after these disasters occur. What’s more, even long after snowstorms are over, snow can get blown back onto the roadway, requiring agencies to plow or push back the snow to clear the roadway. Significant snow accumulation, particularly on a “heavy” snow winter season, drives up maintenance cost for these agencies. Snow drift problems typically occurs on long, flat, rural stretches of highway. To create a snowdrift prevention plan, designers start by analyzing the terrain on both sides of the road. Determining how and where the snow is being picked up and drifted back onto the roadway is important in choosing which solution best suits the road.

Using that analysis, the following three options should be considered for minimizing snowdrifts and avoiding dangerous pileups:

Option 1: Wider Ditches

If there is adequate space, the best option is to have a wide ditch next to the roadway to create a “bowl” effect. These are ditches that serve as another area to capture the snow. Since roads are typically higher than the ditches, it blocks the wind and prevents snow from blowing back onto the roadway. This option requires a lot of room and typically involves additional right of way. If feasible, it is the top choice due to cost and maintenance. 

Option 2: Living Snow Fence

A living snow fence consists of trees, shrubs, or hay bales along the roadway. Farmers can work with their local department of transportation to line the road with hay bales, providing a cost-effective solution to block the wind from stirring up snow from the fields and on the roadways.

Option 3: Structural Snow Fence

This option looks like a robust version of a vinyl fence used for backyards that acts as a direct wind block. These fences often require coordination with property owners because they typically are on private property and outside of public right of ways.

These above three tactics can work for many roadways, but too often they are built reactively and only after a number of crashes, pileups, and other dangers already occurred. All options require room, more often, outside of public right of way. This requires transparent and consistent coordination with nearby residents. Discussions of the benefits for each tactic is key for the residents to allow any mitigation measures in the property. Because many Midwest states see snow for one-third to one-half of the year, agencies must be more proactive, many are now incorporating these tactics into their original planning and design. The Minnesota Department of Transportation, for example, is currently working on major interstate highways in rural locations and are including analysis of the corridor as part of the project. They have a whole department dedicated to working on snowdrift prevention.

Driver safety in winter is important and proper snowdrift prevention design can go a long way to saving lives, preventing crashes, and making roads safer for all of us. WSB’s transportation team can help advise on ways to make roads safer all year round.

By Steve Lindsey, Director of Transportation, WSB

In 2021, Texas added more people to its population than any other state. For residents, businesses, and communities, it’s critical for planners to meet the immediate needs of citizens, while also planning for the future. For local, city, and county governments, corridor studies play a key role in creating and executing comprehensive transportation design that adapts to and meets the needs of growing communities.

What is a Corridor Study?

Corridor studies examine the relationship between roadways and adjacent land. In more densely populated areas, this can mean figuring out ways to overcome challenges where roadway expansion is limited. For land in development, it means looking at future population growth and where investments are being made to build homes, businesses, and public services.  Corridor studies also help ensure that if opportunities to acquire land becomes available – whether because they are being sold or planned for future development – there is a long-term view on how to best meet transportation needs.

Corridor studies are instrumental to help communities plan for 5, 10, and even 50 years down the road.

Trends in Community Growth

In Central Texas, Austin and the surrounding communities are growing rapidly. It is a technology hub with major companies like Tesla, Apple, Dell, and Samsung employing thousands of people. Densley urbanized areas have seen population growth, and more people are building homes and businesses in communities farther and farther from the city centers as the population grows.

Additionally, with the ongoing pandemic, we’ve seen more people looking to build homes, expand their space, and work remotely. With a hot housing market and population growth, more people are building and expanding into areas that were traditionally more rural or predominantly farmland.

Communities need properly planned transportation infrastructure to help transport people and commerce in those growing areas.

Working with the Experts

For community leaders facing growth challenges and working to plan for what’s next, it can be difficult to know when and where to start. When we partner with clients, we help them explore what opportunities their community can tap into in transportation design, and corridor studies are an important tool to get them and their community where they want to go.