Walk Friendly Communities Engineering Strategies. Carl Sundstrom Walk Friendly Communities Workshop Grandview, MO June 2015

Transcription

1 Walk Friendly Communities Carl Sundstrom Walk Friendly Communities Workshop Grandview, MO June 2015

2 Module Overview Topics Background and purpose Sidewalks Crossings Traffic calming Dan Burden 2

3 Background and Purpose Quality design and operation of streets pedestrian facilities is key for WFC Creates safer streets for all users Design field is always evolving Carl Sundstrom 3

4 Sidewalks Sidewalks reduce pedestrian crash risk by 88% Dan Burden 4

5 Sidewalks Dan Burden The sidewalk corridor is divided into 4 zones: 1. Curb zone 2. Furniture/green zone 5-8 ft. 3. Pedestrian zone ft. urban/suburban main streets 6-10 ft. suburban boulevards 4. Frontage zone 5

6 Sidewalks: Buffer Sidewalk with furniture zone is pleasant to walk on 6

7 Sidewalks: Buffer Sidewalk with buffer creates better driveway crossings Intersection-style driveway redesigned to slow down traffic 7

8 Sidewalks: Driveways Every driveway is a potential conflict 8

9 Sidewalks: Driveways Access management reduces conflicts at driveways 9

10 Why are sidewalks discontinuous? 10

11 Why are sidewalks on one side not OK? 11

12 Principles for safe crossings 12 Dan Burden

13 Marked Crosswalks To indicate to pedestrians where to cross To indicate to drivers where to expect pedestrians At mid-block locations, crosswalk markings legally establish the crosswalk. 13

14 Crosswalk Markings Same crosswalk from two vantage points: Pedestrian view Driver view 14

15 Crosswalks The effectiveness of crosswalks can be increased with: High Visibility Markings Proper location Illumination Signing Advance Yield Lines Median Islands Curb Extensions Signals and Beacons 15

16 Crosswalk Placement C = Compliant P = Possibly compliant N = Not compliant. Markings should not be installed without additional safety treatments 16

17 Crosswalk Placement 2011 Chicago Pedestrian Plan 17

18 Crosswalk Illumination Informational Report on Lighting Design for Midblock Crosswalks FHWA-HRT April 2008 Fig 11. Traditional midblock crosswalk lighting layout Fig 12. New design for midblock crosswalk lighting layout FHWA Report 18

19 Multiple Threat Crash Problem 1st car stops to let pedestrian cross, blocking sight lines 2nd doesn t stop, hits pedestrian at high speed 19

20 Multiple Threat Crash Problem Solution: Advance yield line 1st car stops further back, opening up sight lines 2nd car can be seen by the pedestrian 20

21 Advance Yield Line 21

22 Raised Crossing Island One of FHWA s 9 proven safety countermeasures Simplifies crossing May reduce speeds Road diets provide great installation opportunities 22

23 List all features that improve pedestrian safety? High visibility crosswalks Lighting Pulled back stop bar On street parking Bike lanes Zone system sidewalks ADA Raised crossing island Curb extension

24 Corner Radii Large corner radii: Increase crossing distance Make crosswalk & ramp placement more difficult Allow high-speed turns by cars Small radii are safer for pedestrians 24

25 Corner Radii 25

26 Corner Radii 26

27 Effective Curb Radius 27

28 Curb Radius: Design Vehicle Choose appropriate design vehicles 28

29 Curb Radius: Truck Apron 29

30 Channelized Right Turn Lanes Design the curb radii and the channelization to reduce the turning angle Include a pedestrian refuge island 30

31 Curb Extensions Most focus has been on reducing crossing distance Other advantages: Better visibility (both ways) Traffic calming Room for street furniture Additional on-street parking 31

32 Curb Extensions Inexpensive daylighting options 32

33 Curb Extensions: Drainage 33

34 Curb Extensions: Drainage 34

35 Rectangular Rapid Flash Beacons 35

36 Pedestrian Hybrid Beacons ( HAWK ) 36

37 Pedestrian Hybrid Beacons ( HAWK ) 1 4 Blank for drivers 2 Flashing yellow 3 Steady yellow Steady red 5 Wig-Wag Return to MUTCD - Section 4F.3 37

38 Transit Access Animation 38

39 Transit Access Place crosswalks behind bus stop 39

40 Transit Access 40

41 Intersections Features of pedestrian-friendly intersections: Tight Simple Square Slow speed Easy to understand Avoid free-flow movements 41

42 Intersections Competing interests of the different street users can be significant at intersections Delay Safety Conflicts Crossings Visibility Accessibility 42 Laura Sandt

43 Roundabouts Often operate with shorter delay Can help address safety and efficiency concerns Design determined by many variables Construct the smallest diameter roundabout necessary Careful design to keep speeds slow Benefits to pedestrians are easiest to obtain with single-lane roundabouts Construct crosswalks at least one car length from the roundabout entrance

44 Intersections Motorist LOS signalized at intersections Intersection size, and specifically the width of each street approach, affects functionality for all users Capacity, delay, and queue analysis should be considered in light of land use, network, and street context 44

45 Intersections Pedestrian improvements at signalized intersections Good geometric design Crossing islands Convenience of pedestrian signals Reduced conflicts with turning vehicles 45

46 Intersections People will cross where convenient and perceived to be safest 46

47 Signalized Intersections Improving convenience and ease of use of pedestrian signals Proper pushbutton placement Need and placement of pedestrian signal heads Signal timing for pedestrians Countdown Signals Intelligent Transportation Systems (ITS) 47

48 Signalized Intersections MUTCD Recommendations: In line with crosswalk; Buttons at least 10 apart; Between 1.5 and 6 from curb Button face parallel to xwalk MUTCD Sec. 4E.08 48

49 Signalized Intersections 49

50 Pedestrian Signals In general, use signals wherever pedestrians may be present (if in doubt, install them) Ped head should be placed here (height: 7 10 ) 50

51 Accessible Pedestrian Signals (APS) Provide ped signal information in audible and vibrotactile format Benefit all pedestrians by providing redundancy The 2009 MUTCD describes the features of APS, but does not require them Future accessibility standards and future MUTCD editions will likely require APS for all ped signals 51

52 Signal Timing At high-use crosswalks, pedestrians should get a signal at every cycle (pedestrian recall) 52

53 Signal Timing Use Short Signal Cycle Length Long wait causes stacking: pedestrians wait in street, or don t wait and cross against the signal 53

54 Signal Timing Pedestrian countdown displays required for new signals 54

55 Turn movements often result in conflicts 55

56 Signal Phasing Protected Vs. Permissive Left Turns Converting permissive left turns to protected only left turns may reduce all crashes by 70% 56

57 Restricting Turns on Red Consider No Turn on Red signs where there is: Poor sight distance between vehicles and peds; An unusual number of ped conflicts with turns on red (compared to turns on green); An exclusive pedestrian phase; or A leading pedestrian interval 57

58 Signal Phasing Leading Pedestrian Interval (LPI) WALK comes on at least 3 seconds prior to the green signal; pedestrians enter crosswalk before turning vehicles arrive there. Note: Without APS, pedestrians with vision impairments cross by listening to vehicle movement. APS should be used with LPI 58

59 Leading Pedestrian Interval Where do the extra 3-5 seconds come from? Major Street Peds need 30 seconds to cross Minor Street Vehicle queue needs less time to clear 59

60 Balancing act Typical existing conditions with far side stops on one road Source: NCDOT, Toole Design Group 60

61 Balancing act Add a median refuge and reduce corner radii and install two curb ramps each corner Source: NCDOT, Toole Design Group 61

62 Balancing act Add leading pedestrian interval, install bus shelter, lights and trash can Source: NCDOT, Toole Design Group 62

63 Balancing act Add bike lanes on roadway Source: NCDOT, Toole Design Group 63

64 Interchanges Critical connection for all users High speeds and conflict areas an issue Design guidance: Avoid free-flow on and off ramps Construct ramp turning angles as close to 90-degrees as possible Provide high visibility crosswalks in urban and suburban areas

65 Interchanges Design or modify ramps to terminate closer to 90 65

66 Bridges Key links for all modes Often the only connection for pedestrians and bicyclists Long-term investments Infrequently replaced 66

67 Example: South Tryon St, Charlotte Freeway crossing between neighborhoods Poor pedestrian & bicycle facilities 67

68 Example: South Tryon St, Charlotte 68

69 Example: South Tryon St, Charlotte June

70 Grade Separation (over/underpass) Why are they not effective for street crossings? They add out-of-direction travel When are they useful? To connect land uses separated by a roadway How can you increase their effectiveness? By providing a direct route By providing security 70

71 Grade Separation 71

72 Grade Separation 72

73 Grade Separation Elevated roadway allows open, airy undercrossing 73

74 Grade Separation To connect buildings To connect land uses To cross freeways Light rail stations 74

75 Traffic Calming What is Traffic Calming? Traffic calming is a way to design streets, using physical measures, to encourage people to drive more slowly. Self-enforcing roadway design Can provide the visual cues that encourage people to drive more slowly 75

76 The Need for Traffic Calming Relatively high speeds in neighborhoods Cut-through traffic Designs may also provide less tangible, but equally important results Typically placed in residential or main street locations Provide a balance among modes 76

77 Traffic Calming Determine the source of the problem Why do people cut through neighborhoods? Traffic backup on main route More direct connection Why do people speed? Make up time due to delay on main route 77

78 Traffic-Calming Issues Safety Impact of traffic operations Lack of proven design standards Liability Emergency/service vehicle access Impacts on bicycling 78

79 Types of Traffic Calming Speed control Vertical deflection Horizontal deflection Horizontal narrowing Volume control Divertive, restrictive Passive Combined measures 79

80 Speed Control Vertical Deflection Speed hump & table Raised crosswalk & intersection Very effective at speed reduction Inexpensive Accommodate bicyclists Increased motorist yielding Issues Emergency vehicles Discomfort Noise Drainage 80

81 Speed Control Horizontal Deflection Traffic circle High crash reduction Aesthetics Accommodate bicyclists Issues Emergency vehicles 81

82 Speed Control Horizontal Deflection Chicane Adds landscaping Easy to negotiate by large vehicles Issues Bicyclists May reduce on-street parking Neckdowns (curb extensions) Increase pedestrian and amenity space Reduce turning speeds & crossing distance Issues Bicyclists Drainage 82

83 Speed Control - Passive Passive or Cross-Sectional Measures Gateways Landscaping Specific Paving Treatments Slow Zones 83

84 Speed Control Benefit: Space created by traffic calming can be used in stormwater management 84

85 Volume Control Full closures, half closures, diagonal diverters Lower volumes while maintaining ped/bike access Issues Cause circuitous routes Limit access Can be expensive 85

86 Traffic Calming Site Selection Curb extensions Left turn movement around traffic circle Neck down Diagonal diverter Truncated diagonal diverter Chicane Traffic circle Cul-de-sac Curb extensions 86

87 Traffic Calming Trials & Temporary Installations For new calming plans - lay out design with cones or temporary curbs, barriers and/or markings. Allows emergency responders, residents, and others to test and fine-tune the design Source: Source: Source: Source: wikipedia.org 87

88 Traffic Calming Example - Seattle Phase I Step 1 - Preliminary Assessment Step 2 Neighborhood Speed Monitoring Step 3 SDOT Review Phase II Work with the community to identify which (if any) physical traffic calming measures may be effective at reducing speeds 88

89 Resources NACTO Urban Street Design Guide PEDSAFE FHWA Road Diet Informational Guide FHWA Proven Safety Countermeasures

90 Exercise 90