'Vision Zero' road safety projects in Seattle found unlikely to have negative impacts on local business sales

Seattle is routinely listed as one of the most walkable and bike-friendly cities in the nation. The city government has committed to Vision Zero, which aims to eliminate traffic deaths and serious injuries completely by 2030 and embarked on a slew of infrastructure projects: expanding the city's bike network, redesigning high-crash intersections, and enhancing crosswalks to protect pedestrians.

Such safety projects sometimes meet opposition from local business owners, who worry that reduced parking and disruption to regular traffic flow will hurt their bottom line.

New research from the University of Washington suggests those worries are unfounded. Published in Injury Prevention, an analysis of seven safety projects across Seattle found they had no negative impact on the annual revenues of nearby businesses for three years after construction began. The results could help city officials gather support from local business owners and remove a barrier to fulfilling Seattle's Vision Zero pledge.

"Some business owners may be concerned that Vision Zero pedestrian safety projects lead to a trade-off between safety and economic viability. Our research found there is no economic harm in improving safety, and such projects offer the health benefits of reducing injuries," said study co-author Andrew Dannenberg, a UW affiliate professor of environmental and occupational health sciences and of urban planning.

The study was led by UW alumnus Daniel Osterhage, who completed the research for concurrent master's degrees in public health and urban planning and now works at the Bill & Melinda Gates Foundation.

Researchers identified seven road safety projects of varying types, from the addition of bike lanes and crosswalks to speed limit adjustments and the removal of traffic lanes. The project sites were in six of Seattle's seven council districts—they could not find a suitable project in West Seattle—and were all initiated between 2006 and 2014. All seven sites were commercially zoned and close to similar commercial zones that remained unchanged.

Using revenue data that each Washington business submits to the state, researchers established a baseline of taxable sales for businesses adjacent to each safety project, as well as for businesses in the nearby comparison areas. Researchers included only businesses that the state Department of Revenue database identified as "retail trade," "accommodation and food services," and "other services." They excluded businesses from sectors that are less reliant on street-level activity, like manufacturing or construction.

In the three years after each safety intervention, researchers found no significant difference in the year-over-year change in revenue of the businesses in the intervention and comparison sites. On average, taxable sales increased in both the intervention and comparison sites over time and at largely the same rate.

"If there had been a major impact of taking away parking spaces or disrupting traffic leading to a loss of business, you would expect sales to go down in places that had the interventions and not go down in the comparison sites," Dannenberg said. "In fact, they stayed about the same, within statistical range. The sales data do not suggest any economic harm occurred; in fact, there were a few instances where the safety interventions might have even helped sales."

The study has some limitations. For example, researchers did not examine whether certain types of businesses might have been affected differently than others or how factors like the supply of nearby parking spots unaffected by construction might have impacted the results.

Dannenberg, who serves on the Seattle planning commission, believes this work may help facilitate communication between city planners and business interests.

"A walkable environment generally encourages business," Dannenberg said. "I think this work has implications that will be useful to policy makers who work on pedestrian safety and livable community issues."