Designing for Older Drivers - CEProfs by hcj

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									Fall 2012
   Many elderly live in poverty, ill health, and
    inadequate housing
   Increasingly, many of those over age 65 will be
    very old—over age 80–85. In the United States,
    the number of those over age 85 grew 300%
    between 1960 and 1996—to 3.8 million people,
    comprising 1% of the U.S.
   By the middle of the next century, 1 in 20
    Americans will be over age 85
   Women live longer than men (more female
    drivers)
Values can be used for computing the sight distance
at intersections
Recommended Design: Skewed Intersection
● In the design of a new facility (or re-design), all intersecting
highways should meet at 90o
● If ROW is restrictive, the skew angle should be no less than
75o




● If skewed angle smaller, a RTOR prohibition is recommended
Recommended Design: Receiving Lane Width
● 12-ft lane and 4-ft shoulder (critical task: lane positioning)
Recommended Design: Channelization
● Raised channelization with sloping curbs preferred over
pavement markings
● Use retroreflectorized marking maintained at minimum
luminance level
● provide acceleration lane for right-turn channelization
Recommended Design: Sight Distance Requirements
● PRT should be above 2.5 seconds for left, right and crossing
● Use a minimum of 8.0 seconds for a left-turn from a stopped
maneuver
Recommended Design: Left-Turn Geometry & Signing
● Provide positive offset design with unrestricted sight distance
● Use truck design templates whenever there is a high
probability of truck traffic
● When positive offset design is not possible, provide adequate
signing and pavement marking
Recommended Design: Curb Radius
● 25 ft to 30 ft to minimize pedestrian crossing and moderate
the speed of turning vehicles
Recommended Design: Traffic Control for Left-Turn
Traffic
● Use separate signal heads
● Use protected-only signals whenever possible (leading rather
than lagging)
● Install “LEFT-TURN YIELD ON GREEN” sign
● Green arrow followed by left arrow and then solid red circular
red
Recommended Design: Street Signs
● 6-in minimum size
● Use overhead-mounted street signs with mixed-case letters
● Use redundant street-name signs (not mandatory)
● If different street names, the names should be separated
and accompanied by directional arrows
Recommended Design: One-Way/Wrong-Way
Recommended Design: One-Way/Wrong-Way
Recommended Design: Stop Controlled
● Use supplemental sign under stop sign
Recommended Design: Pedestrian Crossings
● Use 2.8 ft/s seconds walking speed




      Where right-turn lane     Two-stage crossing
      is channelized            (median refuge island)
Recommended Design: Pedestrian Crossings
Recommended Design: Exit Signing & Ramp Gore
Design
● 1-in letter for every 33 ft distance
● Mixed-case font for overhead signs
Recommended Design: Exit Signing & Ramp Gore
Design

								
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