Ways to reduce traffic congestion in urban areas

The severity of traffic congestion has increased in the U.S. in recent decades, according to a 2020 report from the Association for Commuter Transportation (ACT) in partnership with the U.S. Department of Transportation (USDOT).

“In 1982, the average person living in one of the country’s 75 largest cities faced seven hours of travel delay per year,” the report states. “By 2001, that figure had shot to 26 hours of delay per year, and the most severely congested periods of the day — once known as the ‘rush hour’ — stretched to cover nearly six hours of each day … with the average ‘rush hour’ trip taking nearly 40 percent longer than the same trip at other times of the day.”

While traffic congestion prevention has advanced over the past few decades, many cities still struggle to deal with it effectively. The USDOT found that between 1980 and 2021, the U.S. built more than 870,000 lane miles of highway, yet pre-COVID-19 congestion was worse than it was in the early 1980s.

Many ways that city and roadway engineers approached road design in the past haven’t proven effective at limiting traffic congestion, such as the move to expand city highways. By prioritizing a monolithic route and disincentivizing diverse roads and travel methods, engineers have unintentionally added to city congestion.

However, well-researched and proven solutions to traffic congestion problems exist. Earning an advanced engineering degree, such as a Master of Science in Civil Engineering, can prepare individuals to design alternatives to city highways that use developing transportation methods and innovate on current road systems plagued with traffic congestion

Traffic Problems

Primary causes of traffic congestion include the following, according to USDOT:

• Traffic accidents blocking lanes
• Difficult weather conditions
• Unexpected spikes in traffic demand
• Traffic bottlenecks
• Disabled traffic control equipment

In many cases, multiple factors can occur at once. One cause of traffic congestion can lead to another, such as when the onset of challenging weather for road travel generates a rise in traffic as drivers rush home.

Traffic creates more problems than just commuting delays. Traffic congestion can cause compounding issues for delivery drivers and the supply chain, slowing the restocking of food and other essentials to communities that don’t have many local sources. High congestion can also influence the public’s perception of a community. It may discourage new businesses and potential residents from moving to the area, for fear of constant traffic.

Traffic Congestion Solutions

Despite the many causes of roadway congestion, civil engineers have tools to reduce its effects and, in some cases, prevent it. More innovative road design can help direct the overflow of drivers onto side roads, reducing the chance of traffic congestion. Alternate transportation infrastructure, such as bus lanes, bike lanes, and sidewalks, can provide travel options outside private vehicles. Investment in public transportation can expand those options even further.

Here are a few more details on some of these traffic congestion solutions.

Smart Road Design

One of the easiest ways to improve traffic congestion is to remove the issue of congestion arising from too many people trying to travel at once on any given road. When a civil engineer’s design offers alternative routes to the same destination, this can help reduce the number of vehicles in high-traffic areas. This allows all streets to share the load of traffic and reduces the number of times drivers wait in it.

Another solution is to reduce the number of lanes available to private vehicles, in favor of public transportation. By exchanging a few open roadway lanes for bus lanes, carpool lanes, or even sidewalks, a civil engineer’s design can reduce the overall number of vehicles on the road, as some potential drivers may opt for another form of transportation that’s cheaper or better fits their lifestyle.

Of course, there will always be drivers who require or choose to drive their own vehicles. However, reducing the overall number of vehicles on the road by providing other options can reduce the potential for congestion.

Alternative Transportation Infrastructure

To increase the use of alternative transportation methods, cities and infrastructure planners have recognized the importance of providing the necessary infrastructure to ensure these methods are safe and efficient. Many cities are increasing their investments in amenities such as bike lanes, carpool lanes, bus-only lanes, bus tunnels, trolleys or streetcar tracks, and more.

The degree of effectiveness expected from these types of designated alternative-transit infrastructure is increased by the outright removal of conventional vehicle lanes, according to an article by Streetsblog. Creating wholly separated streets or exclusive spaces more effectively streamlines traffic than simply painting lanes or messages on existing pavement. Transit design will become an increasingly vital part of urban planning and revitalization efforts in the coming years.

Public Transportation Investment

A 2022 report by the United States Public Interest Research Group (USPIRG) highlights the necessity of increasing investment in public transportation offerings across the country. Cited reasons for increasing public transit use include reducing oil consumption (USPIRG estimates that even current public transit usage saves billions of gallons a year), reducing traffic congestion, and decreasing our national environmental footprint.

Additional quality of life and economic advantages accompany avoiding personal vehicle ownership, such as no longer needing to budget for vehicle maintenance and gas costs. Investing in public transportation can fuel job market growth more robustly than equivalent spending on highway maintenance or spending projects. While city planners or local legislatures often scrutinize significant public transport overhauls because of the perceived high cost, sometimes less is more.

For example, the Bus Rapid Transit (BRT) system is an alternative to a high-cost metro rail that uses dedicated bussing corridors in metro areas, a more efficient and accessible form of transportation, according to the Institute for Transportation and Development Policy.

Creative minds could take existing public transit infrastructure and create brand-new possibilities that not only curtail a variety of growing problems but provide the capacity for growth for towns, cities, whole states or countries, and beyond.

The field of transportation technology and design is projected to experience rapid growth as a convergence of factors propels it to new heights of relevance and demand. Greater demand for better public transportation will be driven by rising national and global populations; increasing calls to reduce reliance on fossil fuels; decreasing costs of alternative energies and technologies; and slow but steady societal behavior shifts that propel more people into lifestyles that reduce personal vehicle ownership.

Plan Your Route to a Career in Civil Engineering

Traffic congestion problems and their solutions are only one aspect of civil engineering. The online civil engineering master’s degree from Ohio University offers courses such as Traffic Impact Studies, Traffic Parameters, and Transportation Planning Fundamentals that introduce students to important fundamentals about traffic congestion, what causes it, and how best to reduce it.

Learn more about our online Master of Science in Civil Engineering program and master how to effectively supervise, plan, design, construct, and operate the infrastructure that connects the modern world.

Recommended Reading

5 States with the Most Congested Highways in the Country

Four Factors of Smart Highways

What Do Civil Engineer Do for Their Communities?

Sources:

The Fourth Regional Plan, “Reduce Highway Congestion Without Adding New Lanes”

Institute for Transportation and Development Policy, What Is BRT?

Streetsblog, “Three Reasons Why Congestion Decreases When Cities ‘Delete’ Road Lanes”

U.S. Department of Transportation, “Mitigating Traffic Congestion”

U.S. Department of Transportation, “Traffic Congestion and Reliability: Trends and Advanced Strategies for Congestion Mitigation”

U.S. Public Interest Research Group, “The Path to Clean Transportation”

Congestion is the breakdown in traffic flow, reduction in speed and increase in crowding that occurs when a road’s capacity is exceeded. The challenge of congestion is a perennial issue for cities in New Zealand and around the world, and one that is rapidly worsening.

Economic expansion, increased urbanisation, the rise of ride-hailing services and e-commerce, underinvestment in infrastructure and mixed results from various policies and programs are seen as the primary trends that have exacerbated urban congestion in recent years.

A 2018 report by the AA revealed that the average Auckland commuter lost 85 hours to congestion the previous year and that was just on the motorways, “It’s only an average figure, so for a lot of people it’s going to be a lot worse – and it doesn’t take into account all the congestion on local roads or the time required to get onto the motorway down the onramps,” says AA spokesperson Barney Irvine.

Perhaps more telling is the increased urban sprawl. The report found that the distance Aucklanders are travelling is increasing and was up by more than 300 kilometres annually.

“We’re seeing so much growth on the outskirts of the city away from public transport connections and away from places of work and study. That can only add up to more driving and more congestion,” Irvine told Newshub.

Auckland’s population is expected to reach two million over the next decade, with around one-and-a-half-million vehicles on the road. The total time spent driving by Aucklanders is predicted to increase by up to 20 per cent.

As for solutions, Prime Minister Jacinda Ardern says the Government is working on it. “We do need to provide more options for commuters, they need to be able to have a reliable option to take, for instance, public transport – and there’s been underinvestment in that area,” says Ardern.

Causes of traffic congestion

The causes of traffic congestion can vary from city to city and country to country. However, there are some common factors that contribute to traffic congestion around the world. These include:

Economic expansion

In an article by Bloomberg, Matthias Sweet, researcher at the McMaster Institute of Transportation and Logistics at McMaster University noted that, despite the obvious inconvenience caused by traffic congestion, there are some positives to be taken in terms of economic expansion.

It is noted that many American cities with the worst congestion also have the largest economies. Congestion is a sign that a lot of people have jobs to go to which can only be a good thing.

Using data from 88 of the most congested metro areas in the US between 1993 and 2008, Sweet found that higher levels of congestion are initially associated with faster economic growth. But, above a certain threshold, congestion starts to become a drag on growth.

Specifically, congestion seems to slow job growth when it gets to be worse than about 35 to 37 hours of delay per commuter per year (or about four-and-a-half minutes extra per one-way trip, relative to free-flowing traffic). A similar threshold exists when the entire road network gets saturated throughout the course of the day.

“The thresholds make things very complicated,” Sweet says. “It means that congestion, in some cities, is more good than bad. And in other cities, it’s more bad than good.“

Demographic changes and urbanisation

We have already talked about the population shift in Auckland with the average Auckland commute increasing by over 300 kilometres a year from 2017 to 2018 but this is not an issue specific to New Zealand.

In the US, the population continues to grow and shift from rural to urban areas. From 2010 to 2030, the US population is expected to increase 15 per cent, from 309 million to 355 million, and the percentage living in urban areas is expected to rise from 81 per cent in 2010 to 89 per cent by 2050.

This could exacerbate an existing trend—a 160 per cent gain in the US urban population since 1980—that has significantly increased vehicle miles travelled (VMT) in cities. Meanwhile, motor vehicles remain the dominant transportation mode.

While these figures may not be representative of cities in New Zealand, the problems are the same throughout the world. In Auckland, around 62 per cent of development over the next 30 years is anticipated to be in existing urban areas. A further 32 per cent is anticipated to occur in future urban areas with only 6 per cent forecasted in rural areas.

Ride hailing

One of the biggest disruptors to transportation worldwide has been the exponential rise in ride-hailing services. Here in New Zealand, while we are starting to see an increase in ride-hailing apps when it comes to choice, we still lag behind many western countries.

Apps like Uber, Ola and Zoomy are three options here in New Zealand, but globally there are several other options to choose from. Lyft is one of the most popular in the US along with Curb. Ola is India’s version of Uber and Didi is China’s. Grab Taxi, Hailo, Line Taxi, Blue Bird and Kakao Taxi are just a few of the other ride-hailing apps that can be found throughout the world.

This increase in ride-hailing apps means that more cars than ever are on the streets, with people often substituting public transport for ride-hailing options. This contributes to the overall congestion on the roads, putting strain on already overloaded infrastructure.

Rise in e-commerce

Internet-based purchasing is on a rapid growth trajectory. Stuff recently reported that Spending online was up more than $1.2 billion last year to a total of $5.8b compared to 2019, according to New Zealand Post’s e-commerce report.

In December, online spending increased $538 million, up 17 per cent on a year before. Even before the Covid-19 pandemic hit, online shopping was up 10 per cent in the first two months of last year, the report says. In the lead up to Christmas 2020, NZ Post delivered more than 200 parcels a minute, or 2.1 million parcels per year.

While it once seemed likely that on-demand delivery would prompt consumers to reduce trips to malls and retail stores, the expected drop in VMT never materialised due to the resulting increase in single-package deliveries (and smaller vehicle loads), failed deliveries which drive repeat visits, and the high return rate of e-commerce orders.

Underinvestment in infrastructure

A well-run transportation network is critical to limiting congestion, but urbanisation has overwhelmed the infrastructure of many cities around the world.

This has been particularly problematic in the United States, where roads, bridges and tunnels already suffer from a lack of upgrades and maintenance. The American Society of Civil Engineers 2017 infrastructure report card graded U.S. systems a D+ overall. A primary reason for this is the backlog of unmet capital investment needed for highways and bridges: about $836 billion, according to a 2015 US Department of Transportation (DOT) report.

Here in New Zealand, we have the same problems. A report by Infometrics of international data shows that New Zealand has been investing in infrastructure at a lower rate than other comparable countries for the last 30 years.

The chart above from Infometrics shows that New Zealand consistently ranks below Australia, Canada, the United States and the United Kingdom when it comes to investment in infrastructure.

New Zealand has a way to go before we lift ourselves up in the international rankings. The chart below shows the latest non-dwelling investment figures for a range of countries for 2018. New Zealand lies in the bottom half of the pack, which is a reflection of our longer-term performance. Several countries with a lower GDP per capita regularly spend more on non-dwelling construction, including Chile and Estonia – countries that are hardly recognised as economic powerhouses.

How technology and smart transportation solutions help to solve congestion issues

Tackling congestion issues around the world is not straightforward and there are many factors to consider. It’s important for transport authorities and governments to take both short and long term approaches. Solutions must address both supply and demand and understand the trade-off when implementing short term solutions that are often faster and cheaper versus longer-term solutions relating to public transport systems that require significant investment over long periods of time.

It’s also important to look at multi-modal transport options rather than looking at each transport method in isolation. It’s important to consider how different modes of travel can work together to meet the needs of a city or urban area including public transport, private vehicles and parking requirements.

Technology is set to play an important role in helping to reduce congestion around the world. Innovation in the transportation space is happening at a rapid pace. However, the effects of new technologies are sometimes unproven and often unknown.

Pilot projects allow cities to learn from trial experiments without having to jump straight in with a full capital commitment. Once the value of an approach has been established, it can then be scaled across the broader municipality.

In a recent post in our Market Leadership section, we took a closer look at five smart transport solutions that are helping to create smarter cities throughout the world. Within those five solutions, three have a significant impact on congestion, helping people to better plan their journeys and reducing the number of vehicles in urban areas. Here’s a quick recap:

1.      Adaptive traffic signals

Traditional traffic signals use timers and inductive loops to determine when the light should `change. While this is effective, it doesn’t allow cities to adjust the signal cycle when there are changes in traffic flows, leading to congestion. Instead of relying on this outdated technology, smart cities will use adaptive signals to adjust in real-time the management of traffic systems.

According to a report by the US Department of Transportation, adaptive traffic signals are deployed in less than 1% of existing traffic signals in the US. Comparatively, in South Korea, BlueSignal rolled out their AI-driven traffic prediction solution which incorporates adaptive traffic signals with a host of other data including driving speeds, risks and congestion to help predict traffic conditions for drivers, allowing them to make informed decisions and to adapt quickly.

BlueSignal CEO Jason (Seng Tae) Baik said, “In the movie Minority Report, the main character arrives at his destination quickly and safely in his desired timeframe by observing traffic conditions via HUD (Head Up Display). I hope that BlueSignal’s prediction and analysis solution can help reduce the social costs of traffic congestion and create a safer and more comfortable driving environment.”

2.      Parking solutions

Cities around the world are investing in smart parking solutions in a bid to ease the issues associated with finding a parking space and potentially to raise revenue for other, related projects. Singapore, which is aiming to be the world’s first ‘smart nation’, has deployed the use of sensors around the city to accumulate and monitor large amounts of data, which they are using to improve parking, traffic and cleanliness.

In San Francisco, the use of smart ticketing to streamline public transport processes and smart parking, which allows authorities to adjust parking prices in areas based on the number of available spaces, is helping people move more freely throughout the city.

In most cities, the use of sensors to identify empty parking spaces in large, multi-storey car parks is helping to reduce the amount of time people spend looking for an empty space and alerts people to free spaces with the use of warning lights and display boards.

3.      Smart corridors

Sections of roads feature technologies that alert drivers of the upcoming traffic conditions, including any accidents that lie ahead, how long it will take them to reach a particular destination, impending weather events and other obstacles that impact driving. Smart corridors keep motorists “in the know” so that they may plan ahead, which helps to ease traffic.

According to a report by State Tech, states like Wyoming in the US are using V2I (Vehicle to Infrastructure) technologies to help cars and trucks pass congested and hazardous areas safely. They are using V2I technology to send safety-related weather and road alerts to drivers who enrol for the innovative program. With 75 short-range communication devices situated in points of interest, drivers receive traffic information, and officials expect to see a significant lift on the local economy and overall safety among travellers in the area.

Summary

The trends that exacerbate congestion show no signs of weakening, and most cities have not yet fully articulated the steps needed to improve. Nonetheless, plenty of tools are available to help reduce congestion, and numerous forward-thinking cities are implementing them in New Zealand and around the world including Auckland, Wellington and Christchurch.

A proactive approach to congestion can be taken by shifting the trajectory of mobility and making cities far more liveable, with convenient, clean and cost-effective mobility solutions.

Here at NEC New Zealand, we recently signed a long-term agreement with Environment Canterbury and the Christchurch City Council to evolve the current bus network into a smart transportation network. It is initiatives like this that put transportation at the heart of smart growth for a modern city and that help to reduce congestion.

Many of these smart transport solutions are powered by the Internet of Things (IoT) which enables the collection and analysis of huge amounts of data which can then be utilised to improve transportation networks and to implement smart solutions for travellers and pedestrians alike.

Related articles