Highway widening projects often proceed on the assumption that they offer a multitude of benefits. However, decades of experience and data from highway construction and expansion call into question the idea that such benefits are realized. Research makes it clear that highway widenings do not necessarily solve congestion and other transportation problems, in fact, widenings frequently exacerbate the very problems they seek to address and many times create additional problems for highway users and the people living along the corridor.

The New York State Department of Transportation (NYSDOT) is in the midst of planning improvements in the Route 17 corridor spanning Orange and encompassing part of Sullivan County. The project, sometimes referred to as the NYS Route 17 Mobility and Access Improvements Project seeks to modernize the corridor: the needs are identified as addressing non-standard and non-conforming design features, safety and operational deficiencies, and transit capacity, access, and amenities in the study area.

Although a widening has not been called for by the DOT, alternatives that included a general purpose third lane and a high occupancy vehicle –or HOV– lane have been considered. Some interest groups have seized on the third lane alternative and assumed the DOT project will add such a lane. Much of the public discussion, then, has assumed a wider highway along the 45-mile corridor from Harriman to Monticello, NY. In fact, widening the road could actually be the worst way to achieve the desired improvements in the corridor.

Using this project as a case study, this brief provides a primer on the negative impacts of highway widening projects, and why it is critical to assess this project, as NYSDOT is, in the context of an array of mobility and accessibility improvement options.

The rationale for widening Route 17

Analysis by the State Department of Transportation shows that drivers using this stretch of Route 17 experience some congestion on some occasions. Congestion is documented as an issue on occasional summer evenings for drivers heading westbound and some Sunday afternoons for those heading eastbound. Although congestion is documented to occur only about 2% of the time and generally only around specific intersections, some area citizens are calling for a wider road along the entire corridor length. It is believed that the widening, in spite of contrary evidence that is presented in this brief, will reduce this congestion, speed up travel times and reduce commute times.

Supporters of the project also claim that widening the road will reduce idling during these congested times and, therefore, improve environmental outcomes. They further believe that widening the road would provide economic benefits and more regional engagement by creating temporary construction jobs and helping address transportation needs as the region continues to attract new jobs and housing development.

Highway widening and induced demand

Widening proposals are also usually made because perceived congestion slows travel times. Yet, it is well documented that highway widening creates more congestion. This is why:

• When traffic is known to move slowly, people plan trips more carefully. If they can, they travel at times when there is less congestion, to less congested locations or use non-car modes of transportation.
• When there are multiple travel options, people will choose the one that best suits them –the decision of how, where, and when to travel is based on the cost, time commitment, and comfort of the choices.
• By widening a congested road, travel times are initially reduced. Thus, the choice to use that road at that time is made more attractive. People who had traveled at other times (non-peak), who had used other modes (transit), or gone to other places or by other routes now use the newly widened road.
• They quickly use up the newly created capacity. This is referred to as ​“induced demand.”

There are two forces of induced demand – short-term or latent and long-term induced demand.

• Latent demand is the portion of traffic that would use the road today if the trip were faster. The increase in supply (road capacity) allows for more users at once.
• Long-term induced demand is the portion of traffic that is drawn to the area. The increase in supply (road capacity) drives down the [time] cost of the trip, bringing new users into the market.

Inducing demand feeds the vicious cycle of creating more car dependence, which feeds demand for more auto infrastructure, which ultimately results in more auto dependence. The immediate increased usage (i.e. more traffic), makes widening a particularly poor solution for already congested highways.

Case studies of highway widenings

This is not just a theoretical argument. Empirical studies across the world show that in case after case a widened road results in worse, or, at best, the same levels of traffic that prompted the widening. The approach perpetuates a cycle of dependence as depicted in the graphic below. Many studies show the relationship between highway capacity increases and increased travel and traffic. A few are highlighted here:

• Kent Hymel demonstrates a one-to-one corresponding increase in traffic to increases in capacity. I.e., a 10% increase in capacity leads to a corresponding 10% increase in vehicle usage, ultimately leading to the same level of congestion. Unfortunately, after the capacity increase, more people than before are subject to congestion, leading to worse environmental outcomes. Hymel finds that speed gains due to the widening are typically eroded within five years.

• Researchers Susan Handy and Jamey Volker from the University of California have found that increasing the capacity of roadways by 10% can lead to a rise in Vehicle Miles Traveled (VMT) by 3% to 8% in the short term and 8% to 10% in the long term. Notably, they found that evidence suggests relative increases may be smaller in metro areas that have higher baseline congestion and alternatives to congestion than areas like Route 17 with relatively limited existing congestion.

• Brown University economist Nathaniel Baum-Snow demonstrates how highways, by inducing traffic, caused, rather than accommodated, suburbanization.

Induced demand also has negative impacts on local communities by moving congestion from the segment widened to other locations, typically to local residential and main streets where traffic is ultimately destined.

Planners and transportation engineers are increasingly calling attention to the poor track record of addressing congestion by increasing highway infrastructure. In their report ​“A Century of Fighting Congestion,” UCLA researchers discuss how the attempts to address congestion over the last 100 years have often led to worse congestion. Between 2009 and 2017, the United States constructed new roads and lanes equivalent to creating a brand new road that could stretch across our country 83 times back and forth. And yet, time lost in traffic continues to mount. Texas Transportation Institute’s Urban Mobility Report shows yearly delay per auto commuter increasing at about 3.5% per year. The index does not show increases in the number of people stuck in traffic, but that number increases with every highway widening.

Some might argue that this means 249,000 new lane miles is not enough. The fundamental problem is that the auto/highway system is a relatively low capacity transportation system. As demand increases, more options become available to address mobility and accessibility needs. Eliminating congestion entirely is infeasible, and perhaps undesirable, as we discuss later in this brief. The Route 17 opportunity should catalyze NYSDOT and the communities impacted in this corridor to think about making congestion less problematic by enabling more people to avoid congestion by promoting alternate options.

Requirements to modernize and meet federal standards

Some proponents for an additional lane along Route 17 have tied the need for widening to attract ongoing federal support and convert State Route 17 to Interstate 86. There is no three lane in each direction requirement for an interstate highway.

The American Association of State Highway and Transportation Officials (AASHTO) promulgates highway design standards in their ​“Green Book.” AASHTO guidance calls for two lanes in each direction as a minimum interstate standard, and most of our Interstate Highway system is two lanes in each direction.

Critical standards for an interstate include access control (i.e. no intersections), speed recommendations, sight distance requirements consistent with the speed recommendations, and shoulders. Shoulders and lanes are recommended to be 12 wide. There are no requirements on the number of lanes. As a reference, Interstates I-87 and I-84 have two lanes in each direction for most of their routes.

Nearly 75% of the country’s interstate system consists of highways that are configured exactly as Route 17 currently is, with two lanes in each direction. If you exclude urban highways, the percentage increases to 91%. New York mirrors these national trends, with 75% of the state’s interstate system being two lanes and rising to 98% of non-urban interstates being two lanes.

Safety improvements to the existing two-lane road can certainly be made. Such improvements would include longer exit and entry ramps and other improvements like those made in the recent upgrade to Woodbury Commons at Exit 131. However, safety along the route will decline with the addition of a travel lane. Numerous studies show that wider roads tend to cause faster speeds, which increase the severity of crashes, and additional lanes create more conflict points between motorists.

The misconception of economic benefit

Economic benefits due to highway widening can be elusive, and the widening can promote certain kinds of benefits while precluding others. Generally, the claims of clear economic benefits from highway widening fail to consider their varied effects. Research shows that highway infrastructure may facilitate the loss or outflow of economic benefits as much as they might flow into the county where the improvement is made. The road will likely redirect economic development rather than generate new economic development. Moreover, while some industries benefit from lower transportation costs, others suffer due to shifting economic activities. Maintaining the existing roads and bridges may provide better economic benefits than widening the highway.

On the other hand, the economic benefits of investments in transit are highly competitive. An analysis of the American Reinvestment and Recovery Act, showed that 70% more job hours were produced for every dollar spent on public transportation compared to highways. Moreover, road repair produced 16% more jobs per dollar than new road construction. J And the American Public Transportation Association estimates that for every $1 billion invested in public transportation, nearly 50,000 jobs are created. And for every $1 invested in public transportation, $5 in economic returns is generated.

One of the downsides of investing in highway infrastructure is that it leads to further investment in automobiles and fuel, which represent economic resources leaving the region. Other economic development and workforce strategies like investment in transit create on-going salaries that keep money circulating in the local economy, further supporting restaurants, services, and other local jobs. These ​“multiplier” effects undergird the economic outcomes described above.

Beyond the investments, sustainable economic opportunity is more likely to follow compact development that creates local jobs for goods and services. Households also reduce their reliance on vehicles, saving more on the costs of vehicle ownership and freeing up money to spend on other goods and services.

The clearest and most direct economic beneficiary of a highway widening project is the construction industry. A widening project will create new, temporary construction jobs–jobs that could just as easily be created by fixing existing highways and bridges, upgrading Route 17 to a safer road, and investing in local infrastructure.

Widening Route 17 is unlikely to strengthen the region’s long term economic outlook. Once this project is completed–if it is indeed carried out–the jobs created will just as quickly evaporate. Alternatively, investing in making Route 17 safer, upgrading local infrastructure, and planning for a more sustainable future can bring near term construction jobs, and more long term economic opportunities.

Environmental goals should be prioritized

Highway widenings occur at the expense of open space and constrain or preclude our ability to implement sustainable development strategies. Widenings feed the cycle of auto-dependence, as illustrated in the figure above.

The claim by supporters that highway widening will reduce idling and improve the environment is unfounded and contrary to the evidence on induced demand. Idling is likely to be reduced in the short-run, but it would only be true for a very short time, until the highway fills with traffic again in a few years. More importantly, it will fill with more cars and congestion, ensuring greater levels of idling and pollution than currently seen.

This project undermines the state’s environmental goals. It is inconsistent with a variety of plans, including the landmark Climate Leadership and Community Protection Act of 2019. Studies calling for a more sustainable approach to land use and transportation go back much further. The climate law dictates that all state agencies adopt guidance to help the state meet its ambitious climate goals and reduce environmental burdens on disadvantaged communities. While NYSDOT has been pursuing several climate-friendly initiatives across the state, including the Inner Loop North Transformation Project in Rochester and the I-81 Viaduct Project in Syracuse, the agency, like most other state agencies, has yet to adopt official guidance for how it will make policy and project decisions to meet the goals of the climate law.

There is an effort to scale up infrastructure for electric vehicles (EVs), and switching to EVs can help reduce greenhouse gasses. While EVs help with GHG, They can worsen other aspects of car dependence. EVs may be more dangerous due to their weight and sound profile, and tire dust is a major contributor to particulate matter and related poor health outcomes. They also do nothing to reduce congestion.

In recognition of these concerns, the scoping document for the climate law states: ​“Actions to achieve the Climate Act goals and requirements transcend the transition to zero-emission vehicles (ZEVs) and include diversified mobility alternatives; promotion of denser, more diverse, better designed, and more transit-oriented land use and development policies; and implementation of market-based policies to influence travel decisions.” Hence, EVs, if not combined with strategies to promote more environmentally friendly patterns of development and increase other modes of transportation, are insufficient to meet the state’s goals.

The rationale for an alternative plan

There are many ways to address congestion without widening a road. Congestion is often caused by breakdowns or automobile crashes –standard shoulders would make it easier to move these causes of congestion out of the stream of traffic, thus reducing the traffic impacts. Short exit ramps that cause back-ups onto the main road and short entrance ramps that make it difficult to merge are also sources of congestion. Inadequate geometry can be addressed to reduce a great deal of traffic congestion. This section of Route 17 is an ideal candidate for such considerations.

By NYSDOT’s estimates, Route 17 is uncongested a significant proportion of the time. Meaning there is excess capacity most of the time on most of the corridor. There are some trouble spots that can be addressed, like the area around Woodbury Commons at Exit 131–one of the largest areas for congestion on Route 17,which has seen a major project completed to address the issue. Adding 50% more capacity to a facility that mostly meets the current demand is an inefficient use of precious infrastructure dollars when we have other transportation needs that would benefit from funding in this region.

Furthermore, traffic projections assume a continuation of the existing development pattern. A failure to consider alternate development patterns would be an oversight in the planning process.

Mobility is a transportation concept that concerns itself with how far and how fast people move. Accessibility is about how many activities or opportunities people can reach. Mobility in and of itself has little value if there is nowhere to go; mobility is a strategy to create accessibility. Hence, mobility plus land use create accessibility.

A robust mobility and accessibility study, such as is being done in the Route 17 corridor, demands a creative look at coordinating transportation and land use, as that is the best way to ensure accessibility concerns are met.

As development along the Route 17 corridor continues and the area attracts new residents, there is an opportunity to plan for the future more strategically and sustainably. This might be a land use strategy that directs development into existing centers like Middletown, Goshen, Liberty, and Monticello, and creates opportunities for active transport and corridor-level transit.

An alternative development pattern can shift travel to destinations such as stronger town centers, which allow for concentrated job and retail opportunities. This includes choices for meeting both discretionary (e.g. entertainment) and non-discretionary (e.g. groceries) needs.

Stronger centers coupled with smart infill development reduce land loss and environmental concerns by encouraging more compact development. This would allow for opportunities to use a wider range of travel modes. For short trips, people can walk, bike, and use other micro-mobility options like electric bikes and scooters. For longer trips, new transit solutions (e.g. shuttle or bus service) would become more viable to serve movement among town centers.

Doubling down on highway infrastructure where the need is so far from obvious would box the state out from implementing approaches that align with environmental, economic development, and social goals.

Conclusion

The Route 17 widening project is being planned to address current land use patterns, locking the area into continued car dependency, drawing more traffic and ultimately ruining the beauty and unique character of Sullivan and Orange counties.

We all know the pitfalls of auto dependence. To achieve the State’s climate goals, to promote choices across the state, and to ensure a healthy future, we must say no to any highway widening, including along Route 17. Investments in safety, transit, bicycle, and walking infrastructure where appropriate, and commitments to alternative land use patterns are essential. This is the surest path to a future that is more sustainable.