In working with transportation agencies across the U.S., our team often faces questions about the role of safety in accessibility analysis. While we know the safety and comfort of streets clearly impacts access for people on foot or bicycle, the effects of accessibility on overall safety haven’t been clear. Fortunately, leading experts in both accessibility and traffic safety recently teamed up to answer this question.
land use
The argument for ending single-family zoning
An article in the latest issue of the JAPA makes a case for getting rid of single-family zoning in U.S. cities. The authors argue that single-family zoning exacerbates inequality and promotes the inefficient use of valuable urban land. By excluding other types of development, R1 zoning produces a housing scarcity in desirable places, which pushes prices up and excludes all but wealthy residents.
Exploring the relationship between transit supply and parking demand
In a recent study, researchers from Australia look closely at the relationship between parking demand and proximity and quality of service supply of public transit. When other socioeconomic factors were considered, the quality of transit service became much more important than proximity alone in determining parking demand. This will be helpful in the ongoing discussion about where and how to reduce or eliminate required parking as part of development.
LOS to play more limited role in California planning, according to survey
A new survey of planning officials in California finds that most are embracing the shift from highway level of service to vehicle miles traveled for evaluating the environmental impacts of new development projects. While some are ditching LOS altogether, however, many still rely on it to measure traffic impacts.
Growth near transit is key to connecting smaller cities, SSTI finds
A new study by SSTI and the Traffic Operations and Safety Lab at UW-Madison provides a partial roadmap to the future for transit in smaller cities. The study gave Eau Claire, Wisconsin—a city nearing 70,000 people—a look into emerging transit technologies and insight on their residents’ perspectives toward transit. SSTI also laid out a dozen future scenarios, evaluating each one using accessibility metrics.
Dense areas are safer but road design is critical
Dense development patterns offer important safety benefits, according to new research from the University of Pennsylvania, but high-speed roads in dense suburban centers are deadly for pedestrians. This new study confirms what others have already shown—that attention to context is critical to safe road design.
Seattle moves to new transportation level of service guidelines
Seattle is the latest city to move away from traditional definitions of motor vehicle LOS and toward a more multimodal approach in assessing the impacts of new development. On January 14, the Seattle Council is set to vote on new regulations for developments to support changes in adopted transportation level of service. The new regulations will change which development projects require transportation mitigation and increase the minimum size of developments that are subject to a transportation impact analysis.
Modernizing Mitigation: A Demand-Centered Approach (SSTI, September 2018)
This report proposes a new approach to assessing and responding to land use-driven transportation impacts, called “modern mitigation.” Instead of relying on auto capacity improvements as a first resort, this approach builds on practice around transportation demand management (TDM) to make traffic reduction the priority. Based on programs dating to the 1990s in several cities, a modern mitigation program requires certain new land uses to achieve TDM credits.
U.S. cities and developers beleaguered by too much parking, Mortgage Bankers report finds
There are 83,141 households in the city of Des Moines, and 1.6 million parking stalls. Even allowing that some of those stalls are occupied by commuters, that’s a pretty staggering disparity. And even accounting for commuters, peak parking occupancy rates are only 65 percent downtown. These are some of the eye-opening findings from a new Mortgage Bankers Association report on parking supply in American cities. The report argues that localities should do their own parking inventories rather than rely on rules of thumb for parking needs and risk squandering resources.
Estimating the amount people drive based on accessibility measures
How does the built environment influence the amount people drive? Research by SSTI’s Logan Dredske worked to answer this very question. The focus of his research was to create a framework for estimating vehicle miles traveled based on conditions of the built environment. His goal was to use measures of accessibility as the principal proxy for the built environment. The research also converted vehicle miles traveled into greenhouse gas emissions and evaluated the ability of transportation projects to reduce emissions.