People Vehicle Friendly Intersections Agenda Introduction Signals Roundabouts Pedestrian

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					People & Vehicle Friendly
     Intersections
             Agenda
Introduction
Signals
Roundabouts
Pedestrian/Bike Friendly Intersections
Introduction to Intersections


Driving through intersections is one of
the most complex conditions drivers
encounter.
Typical Suburban/Urban
      Intersection
Introduction to Intersections


Disproportionately responsible for
pedestrian deaths and injuries.

Almost 50 percent of combined fatal
and non-fatal injuries to pedestrians
occur at or near intersections.
Introduction to Intersections


2.8 million intersection-related crashes
(44 % of crashes)
8,500 fatalities (23 % of fatalities)
One million injury crashes (48 % of
crashes)


                                        2000
Introduction to Intersections


Traffic improvements that increase
vehicular efficiency can decrease
pedestrian safety.

Pedestrians have not been accorded
equal status with vehicles at
intersections.
Introduction to Intersections


Hazardous intersections
 High-volume
 High-speed
 Multilane
 Complex signal phasing
State Farm: Most dangerous intersection in the United Stat




                    Pembroke Pines, Florida
     Potential Solutions


Ways to achieve substantial reductions
in annual crash figures:

 Provide sustained and consistent law
 enforcement efforts.

 Analyze the reasons for traffic conflicts at
 intersections.
Potential Solutions (Cont’d)


 Engage in innovative and strategic thinking.

 Alter key features of the physical design of a
 highway or street.
      Potential Solutions
Improving intersection safety:

  Eliminate vehicle and pedestrian conflicts
  when possible;

  When not possible, reduce unavoidable
  vehicle and pedestrian conflicts

  Design intersections so that when collisions
  do occur, they are not as severe.
Would you allow your child to cross this street?

             From 103 Feet to 26 Feet
La Mesa, California
Chico, California
AutoTurn
               Agenda
Introduction
Signals
Roundabouts
Pedestrian/Bike Friendly Intersections
We will try:
• on street parking
• narrow lanes
• roundabouts ……
  if it works




                      National Traffic Operations Coaliti
Proactive Management: F
   68% manage “fire
   fighting”

Coordinated Operations: D-
  50%+ do not conduct
  timing reviews every 3-5
  years

Maintenance: D+
  Agencies operate with
  minimum staffing



                          National Traffic Operations Coaliti
    Results if Corrected
Delay would decrease by 15-20%
Travel time would reduce up to 25%
Emissions would reduce up to 22%
Fuel consumption would reduce up to
10%
   TRAFFIC OPERATIONS
Traffic Signals - FAQ’s:
What is the purpose of a traffic signal?
 Direct traffic to stop and to proceed.

 Ensure an orderly flow of traffic

 Provide for pedestrians or vehicles to cross
 an intersection
Traffic Signals - FAQ’s (cont’d):
Reduce the number of conflicts between
vehicles


Will traffic signals prevent intersection
crashes?
  Traffic signals do not prevent crashes.
Traffic Signals - FAQ’s (cont’d):
Traffic signals are not an answer for
every problem intersection:
  Increased rear-end collisions
  Excessive delays
  More congested traffic flow
  Increase speeding between signals
               Agenda
Introduction
Signals
Roundabouts
Pedestrian/Bike Friendly Intersections
Modern Roundabouts are not
      Traffic Circles!
Roundabouts are a solution!

Roundabout vs. Traffic circles/rotaries
  Small diameter
  Low speed
  Yield control of entering traffic
  Channelized approaches
  Geometric entry curvature.
Roundabouts are a solution!

Solution: Roundabouts are a proven
safety solution
 100 % decrease in the fatal crash rate;
 60 % decrease in the total crash rate;
 82 % decrease in injury rate;
Federal funding – 100%
New York state
Clearwater Roundabout




          5 Intersections replaced –
          91 conflicts
Clearwater Roundabout




          32 conflicts
Before




After
Pedestrian Safety
     Roundabout Facts

Roundabouts are 75% more efficient
than signals up to saturation

Properly designed roundabouts help to
eliminate “storage” at intersections
compared with signals

Same traffic laws apply
           Roundabout Design
  Each roundabout should be designed
  specific to the site, don’t “copy”

  Deflection angle on splitter island –
  single most important feature – speed

  Design speeds should be < 25 mph,
  normal speed ranges from 10-20 mph
Federal Roundabout Guide
http://www.tfhrc.gov/safety/00068.htm
     Roundabout Design
Design principle – travel in each
direction should be similar each other

All design is a compromise, that is why
it is important to understand principles

Use AutoTurn

Use speed curves to control speed
Old Redwood Highway looking north




            Cotati, California:
State Highway 99 looking north




         Gridley, California:
State Highway, Bradenton Beach, Florida
State Highway, Bradenton Beach, Florida
Brighton, Michigan (20,000 ADT)
           Agenda
Introduction
Signals
Roundabouts
Pedestrian/Bike Friendly
Intersections
       Walking speeds

Pedestrian speeds - 2.5 to 6.0 ft/sec.
MUTCD recommends 4 ft/sec
Factors that affect walking speed
  Temperature
  Precipitation
  Time of day
  Trip purpose
  Pedestrian volume
 Median Nose
                                       Bike Lanes




Channelized Island

                                      Two ADA Ramps
                                      Per Corner

                     Common Features for
                     Pedestrian and Bike Friendly
 Median Cut
 Full width          Intersections
Keep crossings compact
RIGHT-TURN SLIP LANE DESIGN

                          e
              Wid e A ng l              Tighter angle


                              55 to 60
                              degree angle
                              between
   O                          vehicle flows.
  20 20
          O


                                                 O      O


               OLD                             2 0 20
                                                            New
               Way
                                                            proposal
High speed, low                    Vehicle speeds 14 to 18 mph,
visibility of pedestrians,         good visibility of pedestrians
a real head turner
     RIGHT-TURN SLIP LANE
                          50 to 60 degree angle
                           between direction of
                           vehicle flow.

Cut through
                                25 to 40 feet
medians and                     radius depending
islands for                     on design vehicle
pedestrians          One car length
                     back
                                Long radius
                                followed by
                                short
                  150 to 275 feet
                   radius

                 Bicycle lane
Advance Stop Bar – helps prevent “Multiple Threat”
crashes


                                           2

                                     1




               2

                   1




 Problem: Car 1 stops to let bar, so car 1cross;further
 Solution: place advance stop pedestrian stops car 1
 back; car 1 no which doesn’t stop, and hits pedestrian
 masks car 2, longer masks car 2, which can see and be
 seen by speed.
 at high pedestrian.
..once I was blind, but now I can see

				
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