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LaPlante_ Complete Streets - AASHTO -

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									Complete Streets: Basic
Design Considerations

       John N. LaPlante, P.E., P.T.O.E.
           T.Y. Lin International

             Prepared for the:
       Annual Meeting of the AASHTO
     Highways Subcommittee on Design

                July 15, 2008
What is a Complete Street?


  A Complete Street is safe,
 comfortable and convenient for
   travel via automobile, foot,
       bicycle, and transit.
   An incomplete street:




Too narrow for comfortable 'sharing'
An incomplete street:




 Uninviting for transit riders
    An incomplete street:




Room for vehicles, but no room for people
We know how to build right
AASHTO Ped Guide
      • AASHTO Ped Guide
        published in October
        2004.
       • Included many new
         and innovative
         concepts.
      • Reiterated some often
         overlooked AASHTO
         Green Book guidelines.
Current Green Book




AASHTO Green Book encourages
roadway designers to provide for peds.
“Interactions of pedestrians with traffic
are a major consideration in highway
planning and design.”
 AASHTO Ped Guide




Safety is a key consideration. Peds are the
most vulnerable of all roadway users.
 AASHTO Ped Guide




Accessibility is also key. Ped facilities
should accommodate peds of all abilities.
     Basic Design Elements
•   Sidewalks
•   Crossing the street
•   Medians and islands
•   Traffic signals
•   Crosswalks
•   Crosswalk markings
•   Curb extensions
•   Transit
•   Bicycles
Sidewalks
     AASHTO Ped Guide
Sidewalk Design




Not after space for future sidewalks is all gone
    AASHTO Ped Guide
Sidewalk Design
 “All roadways along which pedestrians are not
   prohibited should include an area where
   occasional pedestrians can safely walk.”
     – Unpaved walkway
     – Shoulders in rural areas
     – Sidewalks in urban areas

  Locations with no sidewalks are twice as
    likely to have vehicle-pedestrian crashes
    than sites with sidewalks.
     Pedestrians can get by without sidewalks on
                      quiet streets
Ashland OR
          Shoulders serve pedestrians in rural areas

Benton County OR
          At a certain point, sidewalks are needed
Canyonville OR
           “Goat trail” indicates sidewalks are needed
Jefferson Parish
    AASHTO Ped Guide
Sidewalk Design
  Set triggers for future sidewalks
         • Development densities
          • Developer requirements
          • Going from open to closed drainage
    The AASHTO “Green Book” states:
“Sidewalks are integral parts of city streets”




       Sidewalks are not added to streets,
            they are part of the street
                               Sidewalks should
                               not end midblock




          Forcing pedestrian
              into street


Fredericksburg VA
    AASHTO Ped Guide
Sidewalk Design
  Sidewalks on only one side of the street?
   – Generally not recommended
   – Lacks connectivity
   – Weakens pedestrian safety by requiring
     unnecessary street crossings
    Mountable curbs are not appropriate on local streets
Casper WY
          Separated sidewalk is uncluttered, pleasant
                         to walk on
Reno NV
           Parkway separation makes it easy to meet
                      ADA at driveways
Salem OR
      Narrow curbside sidewalks are inadequate in
                  commercial areas
Reno NV
Crossing the Street
    Pedestrians want & need to cross the
                street safely




       Pedestrians shouldn’t be terrified crossing the street
Santa Ana CA
   Speed Matters
High speeds lead to
greater chance of
serious injury &
death
Child dart-out: speed is a factor!




                 150’
          First scenario: Speed 25 MPH
100’ = distance covered in 2.5   Driver applies
sec. perception/reaction time       brakes




                     100’


                                   150’
First scenario: Speed 25 MPH
             Driver applies   50’ stopping distance
                brakes          (wet pavement)




      100’                     50’


               150’
First scenario: Speed 25 MPH
   Result: Nothing happens beyond
  one scared child, driver & parent!




      100’                     50’


                  150’
Second scenario: Speed 38MPH
140’ = distance covered in 2.5
                                   Driver applies brakes
sec. perception/reaction time




                    140’


                            150’
Second scenario: Speed 38MPH
                        Driver applies brakes




          140’


                 150’
Second scenario: Speed 38MPH
                        In the last 10’ car slows
                              to 36 MPH




          140’


                 150’
Second scenario: Speed 38MPH
         Result: a high
          speed crash




               150’
   Where do these two scenarios lie on
    the pedestrian fatality risk scale?


Second scenario: Crash speed 36 MPH




First scenario: no crash
Complete Streets Design Controls
          Conventional design
          criteria primarily based
          on:
              Functional class
              Design Speed
        • Complete Streets design begins with
          Target Speed:
          –   Desirable operating speed
          –   Mobility for motor vehicles
          –   Safety for pedestrians and bicyclists
          –   Usually posted speed limit
Defining Mobility
          • Typical experience:
            – 45 mph speed
            – 2 min wait at signal
          Defining Mobility
• Viable alternative:
  – 2-way progression set for 30 mph
     Benefit/Cost Analysis
• Reducing speed from 45 mph to 30 mph
  – For a 5-mile trip, a 3.33-minute delay
  – Assume 30,000 ADT and $20/hr driver cost
  – $12.154 million in loss to economy, right?
• Wrong!
  – Delay for each person is still 3.33 minutes
  – Less time than their daily stop for Starbucks
• Community benefit
  – Slower operating speeds
  – Safer and more comfortable ped crossings
Roadway Capacity Analysis
• Design urban roadways to LOS D
• Designing to LOS C for peak hour means:
  – Unnecessary pavement, waste of tax dollars
  – Increased ped crossing times, thus reducing
    vehicular movement times
  – Increased operating speeds for other 22 hours
Medians and Islands
 Reduce crashes by 40%
                  Basic Principle
Break long complex crossing into two simpler crossings
                   Poor sign placement




      Choosing location for island: must have O & D

Corvallis OR
    In this case, apartments across from bus stop
                       and stores
Corvallis OR
Place cut-through at an angle…
                  Flush median is not much of a refuge

Crystal City VA
             Flush median is not much of a refuge

Atlanta GA
             Replace with a raised island

Atlanta GA
Intersection Design
Small, tight intersections best for pedestrians…
       Simple, few conflicts, slow speeds
     AASHTO Ped Guide
Intersection Design – Curb Radii

– Actual curb
  radius (R1)
– Effective
  radius (R2)
  Keeping it tight: Curb radii




* Impossible move on one-way street
Intersection
geometry:
Large radius
increases
crossing
distance, and
affects
crosswalk &
ramp placement
Effect of large radius on crosswalk




                   Additional area to cross
                   + Higher speed turns


      It’s more than the distance…
Effect of large radius on crosswalk




    Hard to figure out where to cross
Effect of large radius on drivers




           They drive fast…
… ignoring pedestrians
      AASHTO Ped Guide
Intersection Design – Curb Radii

• Use entire
  available width
  to turn into
• Select
  appropriate
  design vehicle
Must consider design vehicles, but don’t choose
        larger vehicle than necessary
We shouldn’t design for the exceptional vehicle
Raised islands at intersection separate
               conflicts
Right-Turn Slip Lane:           Design for pedestrians

                                       Tighter
                                       angle
                            55 to 60
                            degree
                            angle
                            between
                            vehicle
                            flows
            Old Way                              New
                                                 proposal
High speed, head turner
                              Slower vehicle speeds, good
low visibility of pedestrians
                              visibility of pedestrians
Island with fairly good geometry
                        Turn Lanes
         Free Flowflow movements…
            Avoid free-




        … they are difficult for pedestrians to cross
         Prevent pedestrian movements
Asheville NC   Designing Streets for Pedestrian Safety – Interchanges & roundabouts   7-10
Free Flow Turn Lanes




Prevent pedestrian movements
       Free Flow Turn Lanes
  Expressway Ramps




• Right angle intersection where ramp meets cross street
• Design urban exits for 20 mph
 Traffic Signals

Signal timing & other simple
innovative ideas to minimize
pedestrian delay & conflicts
              Use short signal cycle length




   Long wait causes stacking: peds wait in street,
     or don’t wait and cross against the signal
Portland OR
 Set pedestrian signal to recall to “Walk”
when major street is set to recall to green

                                    Peds
                                    should
                                    not be
                                    required
                                    to push
                                    a button
Current system:
1. WALK
2. Flashing DON’T WALK *
3. Steady DON’T WALK
1/2 of Americans don’t understand
   it;
 Is there a better system?
* Flashing red hand/don’t
  walk is ped clearance
  interval
 Very counterintuitive
                Problem with current system:
            Pedestrians not sure if they can start during
Boston MA
                        flashing don’t walk
                   Problem with current system:
               Pedestrians not sure if they can start during
                           flashing don’t walk
Corvallis OR
    Pedestrian count-down signal tells pedestrians
          how much crossing time is left …
Springfield OR
   Pedestrian count-down signal tells pedestrians
         how much crossing time is left …
Reno NV
  Countdown Clocks




  Results from San Francisco:
25% Crash Reduction Factor after
  countdown signals installed
Countdown Clocks in MUTCD


•   The existing option of using pedestrian
    countdown displays will now be a
    requirement for all new ped installations
•   All existing pedestrian signal installations
    should be upgraded with countdown
    clocks within 10 years
•   Only exception is where the duration of
    the pedestrian change interval (flashing
    Don’t Walk) is less than 7 seconds
    Pedestrian signal timing
• Old MUTCD recommends using a pedestrian
  walking speed of 4.0 fps, and at crossings with
  older or disabled pedestrians, use 3.0 fps
• However, recent studies found that 4.0 fps based
  on average walking speeds (not 15th percentile)
• New NCUTCD will use 3.5 fps for FDW and 3.0
  fps for overall WALK phase
Crosswalks
      Basic crosswalk
         question:
   Do crosswalks increase safety, or do they
encourage pedestrians to cross without looking?
          (“false sense of security”)
    Safety Effects of Marked vs Unmarked
Crosswalks at Uncontrolled Locations: Executive
    Summary and Recommended Guidelines




        U.S. Department of Transportation         by
        Federal Highway Administration       UNC Highway
        Research and Development                Safety
        Turner-Fairbank Highway Research
        Center                              Research Center
        6300 Georgetown Pike
        McLean, VA 22101-2296                 March 2002
   Conclusions/recommendations
1. OK to mark crosswalks at ADT <10,000 w/o median
2. OK to mark crosswalks at ADT <15,000 w median
3. Medians reduce crash risk significantly
4. Marked crosswalk alone not recommended on high
   ADT roadways
5. Signalization or other treatments should be
   considered where large portion of pedestrians are
   young and/or elderly
Many locations are suitable for a
       marked crosswalk
     Suitable location for a marked crosswalk:
 Two-lane, ADT <10,000, high use, driver expectancy
Madison WI
      Suitable location for a marked crosswalk:
  Two-lane, slow speed, high use, driver expectancy
Washington DC
Crosswalk Markings
Once the decision has been made
      to mark a crosswalk,
the crosswalk must be visible to
              the

          DRIVER
        Visible Crosswalks




   What the
pedestrian sees


                  What the driver sees
Crosswalk Visibility




Crosswalk Marking Types
      Crosswalk Visibility




Longitudinal markings are more visible to
          driver at a distance
         Visible Crosswalks

                            Continental
                             Markings




   What the
pedestrian sees


                   What the driver sees
Textured xwalks: in theory, more visible.
               Reality?
               What the pedestrian sees
Corvallis OR
               What the driver sees
Corvallis OR
      Supplement textured crosswalks with white
             stripes to ensure visibility

Phoenix OR
  Brick Street with
  asphalt
  crosswalks

  Pedestrian
  perspective




Orlando FL
       Driver
       perspective




Orlando FL
Curb Extensions
    AASHTO Ped Guide
Intersection Design – Sight Lines
                         and Curb Bulbs
                             – Relocate
                               obstructions
                             – Eliminate
                               parking on
                               approaches


                             – Curb
                               extensions
                               when parking
                               remains
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 *
       * corner is “protected”
   Pedestrian is waiting on curb, behind parked car
Salem OR
Curb extension places pedestrian where he
          can see and be seen
A new way to look at curb extensions
Not something you add to a street
Imagine the street w/o on-street parking
Now think of parking as the bonus!
Curb extension integrated with
         the sidewalk
                          Consider this your
                            normal curb line

                    Not this




Fredericksburg VA
Transit
           Transit Objectives

 Ensure transit stops are convenient and
  accessible
 Ensure transit users can safely cross the
  street at every transit stop
 Address transit operators concerns
 Address other road users needs
Transit: designing for successful intermodalism
 Transit: bus is most common mode
Madison WI
 Transit: only choice for many people
Madison WI
 Sidewalks should be wide enough to provide
   space for waiting, boarding and passing.
Widen beyond ADA minimum for wheelchair pad
  Narrow curbside sidewalk provides insufficient
                space for waiting
Honolulu HI
 Narrow curbside sidewalk provides insufficient
 space for waiting especially when bus comes &
                  people board
Honolulu HI
    Bus shelter placement: it should not obstruct
                     sidewalk
Portland OR
 Bus shelters must be accessible (grass around
               it is inaccessible)
Honolulu HI
 Bus shelters must be accessible (grass around
               it is inaccessible)
Honolulu HI
Separated sidewalk allows bus shelter placement in
                   planter strip
 Eugene OR
All known crossing techniques apply to transit stops

 Portland OR
                                  Why?
                      1. Peds can see traffic
                      2. Bus driver can move
                      3. Bus doesn’t run over peds




     Place crosswalks behind bus stop!

Madison WI
Bicycles
       Definition: Bike Route
               System
• “Bikeway” is generic term to cover any
  facility designated for
         bicycle traffic
        Facility Selection
• Shared Roadway
 – Recognizes that most bicycle travel now
   occurs on streets and highways without
   bikeway designation
        Facility Selection

• Signed Shared Roadway

 – Signing “should indicate particular
   advantages to using the route over
   an alternative”
No point in striping local
streets with bike lanes
 Bike lanes most
  appropriate on urban
  thoroughfares

 They get you from one
  part of town to another
  efficiently
 Intersections stop or
  signal controlled – the
  “right way”
 No point in striping local
  streets with bike lanes
         Facility Selection
• Bicycle Lanes
  – Can reduce travel lane
      RELATIVE DANGER INDEX
      Of various types of facilities
 Major Streets w/o bike lanes                             1.28
 Minor Streets w/o bike lanes                             1.04 *
 Streets with bike lanes                                  0.5
 Mixed-use paths                                          0.67
 Sidewalks                                                5.32
(* = shared roadway)
                                                       1.00 = median

  Source: William Moritz, U.W. - “Accident Rates for Various
          Bicycle Facilities” - based on 2374 riders, 4.4 million miles
        Bike Lanes: Effect on Rider
              Characteristics
    Riders on sidewalk
    against traffic
                                        Riders on road
                       25%              with traffic
Total sw riders:               34%
64%

                         39%         1% Riders on road
  Riders on sidewalk
  with traffic                          against traffic

  Riders at sites with sidewalks & no bike lanes
        Bike Lanes: Effect on Rider
              Characteristics
                   Riders on sidewalk
    Riders on sw   against traffic
    with traffic
                        11%
Total sw riders:    13%
24%                                     Riders on road
                   3%                   with traffic
                              73%
 Riders on
 road against
 traffic

    Riders at sites with sidewalks & bike lanes
QUESTIONS?

 COMMENTS?

   CONCERNS?

								
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