Excerpt: Erick Guerra on Our Overbuilt Highway System

A new book from Island Press, Overbuilt: The High Costs and Low Rewards of US Highway Construction, by Professor of City & Regional Planning Erick Guerra, describes how in the US there continues to be a propensity to build roadways, despite the extensive damage wreaked by the creation of the highway system. Charting the history of how our roadway system became overbuilt, Guerra also offers ways to rethink our approach to highway building. In an excerpt, Guerra discusses the need to not only stop building more highways, but to embrace the opportunities of rebuilding existing roadways in new ways.
 

Many urban highways should never have been built. The harm to local neighborhoods, environmental damage, and loss of valuable urban real estate frequently outweigh the benefits to motorists. As shown in chapters 3 and 4, public officials sought to bury Boston’s Central Artery almost as soon as the first segments had opened due to the substantial damage it did to surrounding neighborhoods. A movement to downgrade overbuilt roadway systems is already occurring, with some cities and towns choosing to tear down particularly harmful elevated freeways and replace them with at-grade boulevards. As more highways and elevated structures reach the end of their structural lives and require substantial reinvestment, there is a growing opportunity to rebuild differently.

The Embarcadero Freeway removal in San Francisco provides an early, illustrative example of the benefits of highway removals. Like many urban highways, the Embarcadero consumed valuable central land and cut San Francisco off from its waterfront. Moreover, due to freeway revolts in San Francisco, the Embarcadero never connected the northern Golden Gate Bridge to the eastern Bay Bridge as originally intended. There was already a citizen movement and local government support to remove the Embarcadero when the Loma Prieta earthquake hit the Bay Area in 1989, knocking out sections of the structure and forcing officials to close the freeway to traffic.(1) Faced with the enormous costs of rebuilding the structure, state officials opted for the lower-cost solution of replacing the highway with a boulevard with enhanced transit, bicycle, and pedestrian facilities. Despite traffic engineers predicting traffic chaos and reduced safety, neither materialized. People previously using the highways shifted to other highways, transit, or local roadways. Property values also increased near the boulevard relative to other similar properties.(2) Surrounding land uses have also continued to shift over time. For example, the Ferry Building, no longer hemmed in by an elevated freeway, has become one of San Francisco’s top destinations for tourists and locals alike.(3)

As part of a series of efforts to revitalize Milwaukee, then mayor John Norquist led an effort modeled on the Embarcadero removal to replace Park East Freeway with a tree-lined boulevard and new houses, shops, and other businesses.(4) Federal highway dollars and a share of the increased local property tax revenues from $1 billion of new real estate investment financed the removal.(5) After completing four terms as mayor, Norquist became president of the Congress for New Urbanism, an urbanist advocacy organization, where he continued advocating for freeway removals. Every few years, the Congress for New Urbanism puts out a list called “Freeways without Futures” that highlights efforts to bury or replace urban highways.(6)

Over time, the list has highlighted projects from thirty-one cities in seventeen states and Washington, DC. Some projects have already been removed and replaced with urban boulevards. For example, officials have begun the process of tearing down portions of Route 34 in New Haven, Connecticut. This highway disconnected parts of downtown New Haven and took up twenty-six valuable acres of centrally located land. In 2019, officials closed the Alaskan Way Viaduct, separating downtown Seattle from its waterfront, and began the process of tearing down the elevated structure, tunneling a new underground highway, and building a surface-level boulevard. And, as illustrated by Boston’s Big Dig, burying highways can be extremely expensive. Despite the high costs, federal reserve economists Jeffrey Brinkman and Jeffrey Lin estimate that freeing up land and removing the impacts of surface highways often outweighs these costs. For example, the economists estimate that burying 4.5 miles of Interstate 95 along Philadelphia’s waterfront would increase population by 7 percent within a mile of the freeway, boost land values by 2.4 percent, and cover the estimated $500 million per mile in costs.(7) Other projects on the Freeways without  Futures list, such as Interstate 35 in Austin, have garnered substantial local and national opposition but appear likely to be widened and rebuilt.(8)

Freeway removals remain somewhat limited in scope and scale. Funding is one major challenge. The Reconnecting Communities Pilot Grant Program provides the first-of-its kind dedicated federal funding aimed at undoing some of the harm created by urban highways. The first $185 million of this $1 billion program went to planning and construction grants supporting forty-five projects to study, cap, sink, replace, or add crossings to existing urban freeways.(9) Several Freeways without Futures projects, including Interstate 35 in Austin, have received funding. A particular emphasis appears to be on funding the removal of highways that separate communities, disconnect cities from bodies of water, and consume substantial amounts of valuable land that can be readily redeveloped into new well-located housing, shops, and offices. For all the program’s promise, however, $1 billion is a drop in the bucket. It is roughly one five hundredth of the 2021 federal transportation bill, a fraction of what will be spent on building and widening highways over the same five years, and enough to bury around two miles of urban highway.(10) In short, the program is a promising start but will do little to reduce the overbuilt nature of the US roadway system.

Road diets are another promising, and frequently popular, way to reduce roadway capacity to improve traffic safety and spark local economic development along main streets and other arterials. As state and municipal departments of transportation have spent billions of dollars widening urban arterials to increase capacity and feed the highway system, these major roads have become among the most dangerous and least pleasant. These high-capacity thoroughfares generally make up what cities frequently call their high-injury networks, the roughly 5 percent of roadway that account for 50 percent of serious injuries and fatalities.(11)

The most common road diet is to convert a street with two lanes in each direction to a single lane in each direction and center left-turn-only lane. The removed lane typically makes space for bike lanes, wider sidewalks, or busways. In addition, traffic speeds tend to decrease, and pedestrian crossings get shorter. Studies from California, Virginia, New Jersey, and Rhode Island have all found substantial reductions in crashes, injuries, and fatalities from road diets.(12) Based on the existing research, the Federal Highway Administration recognizes road diets as an effective tool for improving traffic safety, with an expected 19 to 41 percent reduction in crashes after the roadway redesign.(13) In addition to promoting safety, these conversions are also frequently part of a concerted effort to revitalize local main streets and other commercial corridors. They also reflect a pushback against a century of transportation planning and engineering practices that have focused almost exclusively on measuring and prioritizing roadway capacity and traffic speeds.

1) Robert Cervero, J. Kang, and K. Shively, “From Elevated Freeways to Surface Boulevards: Neighborhood and Housing Price Impacts in San Francisco,” Journal of Urbanism: International Research on Placemaking and Urban Sustainability 2, no. 1 (2009): 31–50; John King, Portal: San Francisco’s Ferry Building and the Reinvention of American Cities (Norton, 2023).

2) Cervero, Kang, and Shively, “From Elevated Freeways to Surface Boulevards.”

3) John King, Portal: San Francisco’s Ferry Building and the Reinvention of American Cities (Norton, 2023.

4) John Norquist, The Wealth of Cities: Revitalizing the Centers of American Life (New York: Basic Books, 1999); Congress for New Urbanism, “Completed Highways to Boulevards Projects,” text, CNU, June 12, 2015, https://www.cnu.org/our-projects/highways-boulevards/completed-h2b-projects; Cervero, Kang, and Shively, “From Elevated Freeways to Surface Boulevards.”

5) City of Milwaukee, “Park East Redevelopment,” accessed September 9, 2024, https://city.milwaukee.gov/DCD/Projects/ParkEastredevelopment.

6) Congress for New Urbanism, “Freeways without Futures,” text, 2019, https://www.cnu.org/highways-boulevards/freeways-without-futures/2019.

7) Jeffrey Brinkman and Jeffrey Lin, “The Costs and Benefits of Fixing Downtown Freeways,” Economic Insights 7, no. 1 (2022): 17–22.

8) Megan Kimble, City Limits: Infrastructure, Inequality, and the Future of America’s Highways (New York: Crown, 2024).

9) US Department of Transportation, “Biden-Harris Administration Announces First-Ever Awards from Program to Reconnect Communities,” US Department of Transportation, press release, February 28, 2023, https://www.transportation.gov/briefing-room/biden-harris-administration-announces-first-ever-awards-program-reconnect-communities.

10) Brinkman and Lin, “The Costs and Benefits of Fixing Downtown Freeways”; Federal Highway Administration, “Highway Statistics.”

11) Wes Marshall, Killed by a Traffic Engineer: Shattering the Delusion That Science Underlies Our Transportation System (Washington, DC: Island Press, 2024), 179.

12) Kimberly Venegas et al., “Take the High (Volume) Road: Analyzing the Safety and Speed Effects of High-Traffic-Volume Road Diets,” Transportation Research Record 2678, no. 6 (June 1, 2024): 74–86, https://doi.org/10.1177/03611981231193630; Robert B. Noland et al., “Costs and Benefits of a Road Diet Conversion,” Case Studies on Transport Policy 3, no. 4 (December 1, 2015): 449–58, https://doi.org/10.1016/j.cstp.2015.09.002; Yuying Zhou et al., “Safety Effectiveness of the Road Diet Treatment in Rhode Island,” Transportation Research Record 2676, no. 7 (July 1, 2022): 24–31, https://doi.org/10.1177/03611981221076433; Peter B. Ohlms et al., “How’s That Diet Working: Performance of Virginia Road Diets,” April 1, 2020, https://rosap.ntl.bts.gov/view/dot/54878.

13) Federal Highway Administration, “Road Diets (Roadway Reconfiguration),” accessed August 8, 2024, https://highways.dot.gov/safety/proven-safety-countermeasures/road-diets-roadway-reconfiguration.