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Chapter 4: Planning context
Pages 30-41

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From page 30...
... Sustained equitable engagement is key to repairing past harms associated with the transportation sector and ensuring that future investments help heal communities. This Guide explicitly prioritizes safety, beginning with the least protected users, as directed by the USDOT's 2022 National Roadway Safety Strategy.
From page 31...
... Figure 4-4. Example street designed for all modes.
From page 33...
... Without clear guidance on what constitutes safe street design for all modes, practitioners are challenged to make safety the top priority. This Guide presents an approach to cross-section selection that begins with creating safe spaces for all street users.
From page 34...
... 5-2 Roadway Cross-Section Reallocation: A Guide pedestrians may use the street itself for a midblock crossing or to exit from a parked car. Vehicular speeds should be slow enough to allow these activities safely and comfortably.
From page 35...
... Similarly, street crossing opportunities for people walking and bicycling are often spread far apart and designed to minimize delays for drivers, resulting in uncomfortable and unsafe conditions. Benefits of a Network Plan and Clearly Articulated Street Function The importance of a clearly expressed street function goes beyond organizing prescribed features and facilities into categories.
From page 36...
... A Safe System approach (which puts rational, data-driven speed management at the core of every street-design project) is built on the idea that designers can implement a street designed to a target speed that matches its function and context.
From page 37...
... Safe streets and safe speeds are the direct focus of this chapter for two reasons: 1. Planning and engineering practitioners can directly enhance safety through street design and speed management.
From page 38...
... Although varying widely in shape and style, and with posted speed limits commonly between 20 and 35 mph, local access streets present a significant opportunity to maximize safety and provide consistency throughout a network. Access streets should not be designed for speeds above 20 mph.
From page 39...
... Example access street designed for slow speeds in Minneapolis, MN. THE LIKELIHOOD OF FATALITY INCREASES EXPONENTIALLY WITH VEHICLE SPEED32 100% 75% 50%Likelihood of Death 25% 0% Hit at 23 mph, 10% of people will die Hit at 32 mph, 25% of people will die Common Speed Limits on Urban Arterials Hit at 50 mph, 75% of people will die Impact Speed 15 MPH 25 MPH 35 MPH 45 MPH 55 MPH Figure 5-5.
From page 40...
... This may have the adverse effect of decreasing the number of bicyclists and minimizing the perception of safety, so, even if low speeds make for an objectively safe street, the network may decline. On streets with traffic volumes greater than 2,000 vehicles per day, additional engineering measures such as traffic-calming, painted bike lanes, or marked crossings may be necessary to maintain a high level of comfort and usability.
From page 41...
... Speed Management Speeds on distributor streets can be influenced by various cross-section design decisions (e.g., travel lane widths, the number and type of lanes, and the use of vertical elements such as median islands)


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