Designing Complete Streets: What you need to know

Transcription

1 Designing Complete Streets: What you need to know

2 Getting from this

3 to this. Continuous sidewalk Buffer w/trees Bicycle lane Raised median Buildings close to the street

4 Flexibility in design

5 Design and context

6 Design Speed and Design Vehicle

7 The need for Conventional design theory: Speed = Capacity

8 Speed vs. design scale Speed Scale/design geometrics

9 Wide lanes

10 Setbacks

11 Big intersections

12 Designing for speed

13 Designing for speed?

14 Design speed does not determine capacity in urban areas intersection operations/delay is major determinant.

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16 Design Scale in Walkable Streets

17 Speed vs. design scale Speed Complete Streets Scale/design geometrics

18 Speed vs. Pedestrian safety Source: New Jersey DOT

19 Recommended practice for Complete Streets Maximum posted (target) speed 35 mph Maximum design speed 40 mph

20 Selecting the appropriate design vehicle Don t design for the exception

21 Road Diets

22 Many overly wide roads could use a road diet

23 What s a road diet? Classic road diet shrinks 4 lanes to 3 + bike lanes

24 Another road diet example Classic road diet shrinks 4 lanes to 3 + bike lanes

25 What else does a road diet do? Creates room for wider sidewalks

26 What else does a road diet do? Encourage appropriate operating speeds (consistent with design speed) Reclaims ROW for other features Bicycle lanes Wider sidewalks Street trees On-street parking Wider medians/turn lane Etc. An inexpensive tool for retrofitting existing streets

27 Four lane to three-lane conversion

28 Four to three lane reductions can actually enhance safety and capacity

29 Four lanes versus three X vs.

30 Four lanes versus three X vs.

31 Road Diet on Washington Street

32 Road Diet on Washington Street

33 Case study research Source; Converting four lane undivided roadways to a three-lane cross-section: Factors to consider. Iowa State University and Iowa DOT

34 Guidelines for Complete Streets: Lane reductions

35 Sidewalks and paths

36 Design elements Sidewalks Frontage zone Pedestrian zone Eight feet min. Furniture Zone (clear zone)

37 Minimum width is unacceptable

38 With higher vehicle speeds & volumes wider is better

39 On-street parking

40 On-street parking: Relationship to livable communities Intended for low-speed environments Provides buffer between roadside/pedestrians and traveled way

41 Back-in angle parking Improves visibility Improves safety for bicyclist Source: Walkable Communities, Inc.

42 Bulb-outs & curb extensions Provide visibility at intersections and mid-block crossing

43 Bicycle lanes

44 On-street bicycle facilities Shared facility Wide outside lane Designated bicycle lane Paved shoulder

45 Lane width reductions Existing Proposed Stripe 4 bicycle lane Reduce travel lane width to 11 Eliminate offset (design speed =< 35 mph)

46 Will bike lanes create safety issues?

47 Bike lanes can make streets safer, by. Creating appropriate lane widths Encouraging appropriate operating speeds Creating a soft buffer between travel lanes and roadside objects

48 Transit facilities

49 Transit facilities: relationship to complete streets Safe, deliberate facility for transit access Establishes legitimacy of transit Improved bus/vehicular operations and safety

50 Integrate transit with street design

51 Medians

52 Medians: Relationship to Complete Streets Safety Reduced vehicular crashes Crossing refuge for pedestrians Roadway character Can encourage more appropriate operating speeds Terminates long vistas Opportunities for landscaping enhancement

53 Medians improve safety at driveways

54 Medians and Islands Reduce crashes by 40%

55 Medians reduce crash risk for random midblock crossings

56 Flush median is not much of a refuge

57 Flush median is not much of a refuge

58 Basic Principle Break long complex crossing into two simpler crossings

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62 Street trees and fixed objects

63 Relationship to Complete Streets Important buffer between pedestrian and travel lanes Contributes to roadway character Contributes to driver perception of speed

64 Plans Preparation Manual Ch. 2 Horizontal clearance Distance between the face of the curb and a roadside feature Horizontal clearance

65 Vehicular separation is critical to a walkable environment Pedestrians feel exposed and vulnerable within a constrained ROW, flexibility in clearance is absolutely essential!

66 Intersections

67 Intersection are barriers No/poor treatments Long crossing distance peds feel exposed Higher speed vehicular turn movements

68 Large radii 1. Increase crossing distance and 2. Make crosswalk & ramp placement more difficult

69 Effect of large radius on drivers They drive fast, ignoring pedestrians Tigard OR

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76 Green Streets A green street can be defined as a street designed to: integrate a system of stormwater management within its right of way reduce the amount of water that is piped directly to streams and rivers be a visible component of a system of green infrastructure that is incorporated into the aesthetics of the community make the best use of the street tree canopy for stormwater interception as well as temperature mitigation and air quality improvement ensure the street has the least impact on its surroundings, particularly at locations where it crosses a stream or other sensitive area. The design and construction of green streets is one component of a larger watershed approach to improving the region's water quality, and requires a more broad-based alliance for its planning, funding, maintenance and monitoring Alabama ASCE Summer Conference 76

77 Complete Streets are A way of addressing the needs of all potential users Based on sound engineering judgment and principals Unique to each specific street Safe, efficient and economically viable for all users