Light Rail's Impact: Reducing Phoenix's Pollution

The Valley Metro Rail, also known as METRO, is a light rail system that serves the cities of Phoenix, Tempe, and Mesa in Arizona. The network is part of the Valley Metro public transit system, which began operations in 2008. In the years since, the system has undergone several expansions, with numerous plans for extensions in the works. However, the light rail system in Phoenix has faced opposition, with critics arguing that it is a waste of money and does not significantly reduce traffic congestion or air pollution. Despite the controversy, the light rail system has continued to expand, with the city investing in its development.

Light rail's impact on Phoenix's air quality

The Valley Metro Rail (METRO) is a 29.8-mile light rail system that serves the cities of Phoenix, Tempe, and Mesa in Arizona. The network is part of the Valley Metro public transit system, which began operations in 2008. Since its opening, the system has undergone several expansions, with numerous plans for extensions in the works.

The impact of light rail on Phoenix's air quality has been a topic of discussion, with some proponents arguing that it would help mitigate urban traffic congestion and improve air quality. The Phoenix region's urban planning agency, the Maricopa Association of Governments (MAG), conducted a study to project the traffic and air quality in 2020 with and without a 20-mile minimum-operating segment of light rail.

The results of the study showed minimal differences between the scenarios with and without the light rail, with most impacts being fractions of 1%. According to the MAG model, the light rail is expected to reduce vehicle-miles of travel (VMT) in the region by 0.04%, which is equivalent to removing one car out of every 2,500 from the stream of traffic. While this may have a small impact on reducing traffic congestion, it is unlikely to have a significant effect on air quality.

In fact, the Valley Metro environmental impact statement predicts that future pollution levels will be slightly higher if the light rail is built, with carbon monoxide pollution expected to increase. This is because placing the train tracks in city streets reduces roadway capacity for motor vehicles, which can lead to longer travel times and increased fuel consumption, resulting in higher pollution levels.

Despite the potential drawbacks, some expansions of the light rail system have been funded by federal air quality grants, indicating an expectation that the light rail may have a positive impact on air quality in the long run. However, the overall impact of the light rail on Phoenix's air quality remains to be seen, and it is just one of many factors that contribute to the city's air pollution levels.

The cost of light rail construction

Compared to freeway expansion, light rail construction can be more costly per mile. However, light rail tends to be concentrated in urban areas, where right-of-way and property acquisition expenses are higher. Combining highway expansion with light rail construction can help reduce overall costs. For example, Denver's Transportation Expansion Project combined highway improvements with light rail expansion, resulting in a total cost of $1.67 billion for 17 miles of highway work and 19 miles of double-track light rail.

Light rail construction costs can be kept relatively low by utilizing strategies such as minimizing underground and elevated tracks, sharing transit malls with buses, leasing rights-of-way from freight railroads, and coordinating light rail construction with freeway expansion projects. These strategies were employed by the Calgary C-Train, resulting in capital costs of around $24 million per mile. Additionally, higher ridership can improve the cost efficiency of light rail systems, as higher passenger numbers can justify the investment.

In summary, the cost of light rail construction depends on various factors, and there are strategies to mitigate expenses. However, it is important to consider the potential benefits of light rail, such as reduced traffic congestion and improved air quality, alongside the financial investment.

Light rail's effect on traffic congestion

Light rail has been proposed as a solution to traffic congestion in Phoenix, Arizona. However, its effectiveness in reducing congestion is questionable. While light rail can carry more passengers than a standard bus, it also occupies road space that could otherwise be used by motor vehicles, leading to potential increases in traffic congestion.

Advantages of Light Rail

Light rail trains have a much larger carrying capacity than buses, with a three-car configuration able to carry six to seven times as many passengers as a standard bus. This high capacity, coupled with a lower cost compared to subway or elevated tracks, makes light rail an appealing option for urban planners aiming to reduce traffic congestion.

Disadvantages of Light Rail

The construction of light rail tracks in city streets can result in the loss of two lanes of roadway for motor vehicle travel, with three lanes affected where stations are located. This reduction in road capacity can squeeze remaining traffic into a narrower space, impeding the flow of motor vehicles. Additionally, light-rail trains often have priority at traffic signals, further hindering the movement of other vehicles.

Impact on Traffic Congestion in Phoenix

The Phoenix region's urban planning agency, the Maricopa Association of Governments (MAG), conducted a study to compare traffic impacts with and without a 20-mile minimum-operating segment of light rail. The results indicated that the addition of light rail would have a minimal impact on traffic congestion in the region, reducing vehicle-miles of travel (VMT) by only 0.04%. While this reduction may seem positive, it is overshadowed by the region's projected annual 3% growth in VMT, merely delaying impending gridlock by approximately two weeks.

Furthermore, the loss of road capacity due to light rail construction is expected to increase vehicle-hours of travel (VHT), leading to longer travel times even with a reduced number of vehicles on the road. The MAG model projected a 0.45% increase in VHT for the region and a 1.23% increase for the corridor served by light rail, indicating that trips would take longer despite a slight reduction in VMT.

While light rail has the potential to reduce traffic congestion by diverting automobile drivers to public transit, the loss of road capacity due to track construction and the slower speeds of light rail can counter these benefits. In the case of Phoenix, the addition of light rail is predicted to have a negligible impact on traffic congestion, and may even contribute to slightly increased travel times. Therefore, it is essential to carefully consider the potential drawbacks of light rail implementation and explore alternative solutions to effectively address traffic congestion in urban areas.

Light rail's ridership and revenue

Light rail ridership and revenue in Phoenix, Arizona, have been the subject of much debate. The Valley Metro Rail, which began operating in 2008, has seen ridership numbers fluctuate over the years, with a busy period in April 2017 recording a total passenger count of 1,514,456 and an average weekday ridership of 52,910. The light rail system has undergone several expansions since its opening, with at least three more scheduled. As of the third quarter of 2024, the system had a ridership of 10,797,600, or about 32,600 per weekday.

The light rail has also contributed to rapid urban development in downtown Phoenix, leading to additional revenue through taxes. However, the cost of constructing and maintaining the light rail system has been a point of contention. Between 2017 and 2018, the cost of the south-central light-rail expansion nearly doubled, from $704 million to $1.35 billion. Opponents of the light rail argue that these escalating costs show financial irresponsibility, while proponents defend the value of the light rail, citing added benefits such as the downtown hub.

The Phoenix region's urban planning agency, the Maricopa Association of Governments (MAG), conducted a study to compare the traffic impacts of a 20-mile minimum-operating segment of light rail with no light rail. The results showed a minimal difference between the two scenarios, indicating that light rail may not significantly address traffic congestion in the region. However, the addition of light rail is expected to reduce vehicle-miles of travel (VMT) in the region by a small percentage.

Despite the debate surrounding ridership and revenue, the light rail system in Phoenix continues to expand, with several extensions in the works, funded by a combination of federal grants, regional transportation funds, and local dollars from a sales tax increase approved by voters.

Public opinion on light rail

Public opinion on the light rail in Phoenix, Arizona, is divided. In August 2024, Phoenix voters defeated Proposition 105, which would have stopped existing and future light-rail expansion plans in the city. Approximately 180,636 ballots were cast, with 62.33% against Prop 105 and 37.67% in support. This was the fourth time since 2000 that Phoenix voters had rejected proposals to halt light rail projects.

Phoenix Mayor Kate Gallego welcomed the result, thanking voters for "defeated [...] Prop 105" and stating that the vote was about residents "firmly stating what they wanted in their community". The American Public Transportation Association President and CEO, Paul Skoutelas, also praised the outcome, congratulating the "forward-thinking residents of Phoenix" for recognising the essential role of light rail in their economy and community.

However, there is also significant opposition to the light rail in Phoenix, particularly from conservative lawmakers and legislators. Hard-right politicians have killed efforts to expand the Valley's light rail system and are seeking to shut down public transit due to its cost. One example of this opposition is the attempt to include a proviso in a $24 billion proposal that would restrict the use of funds only to operate and maintain existing lines.

The light rail in Phoenix has also faced criticism for events such as the "No Pants Light Rail Ride", which has been described as a "bad idea" that could imperil the future of the light rail by providing ammunition for opponents of public transit.

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