REDUCING ENGINEERING STANDARDS: GOOD or BAD

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REDUCING ENGINEERING STANDARDSGOOD or BAD?

• AASHTO Subcommittee on Design
• Albuquerque, NM
• July 14, 2008

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ILLINOIS EXPERIENCE Widening Resurfacing
Program of early 1970s

• Widened many miles of 18-foot and 20 foot 2-lane
  highways to 24-feet (two 12-foot lanes)
• Minimal shoulders avoided additional ROW
• Almost no alignment improvements (horizontal or
  vertical)
• Eliminated concrete lip curbs
• Widened and/or replaced narrow bridges
• Upgraded traffic signals added breakaway bases
• Created and/or expanded clear zone eliminated
  fixed objects to the extent practical
• NO DOUBT IN MY MIND WE SUBSTANIALLY IMPROVED
  SAFETY even though we did not meet all minimum
  standards

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3R (RRR) Rulemaking Experience

• 1976 Congress redefines Construction to
  include 3Rs resurfacing, restoration and
  rehabilitation
• AASHTO 3R Design Standard (Purple Book)
• FHWA 3R Design Standards
• Ultimate 3R Rulemaking (now 23 CFR 625.4)

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3R (RRR) Rulemaking

• Based primarily on a major research effort
  conducted by FHWA that concluded that
• Greater overall safety can be achieved by
  improving more miles of highways to lesser
  standards than by improving a few miles of
  highway to full standards.

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ARIZONA EXPERIENCE since 1984

• Generally achieve full standards on new or full
  reconstruction projects
• Arizona (ADOT) has not exercised the option of
  adopted separate standards for 3R Projects.
• We are encountering many deviations as we
  improve existing highways including our
  Interstate highways
• We are using the Design Exception process

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The Dilemma to reduce standards or not

• Even with my experience with 3R efforts
  involving improvements that do not achieve or
  meet all standards, I am reluctant to actually
  reduce design standards.
• I believe the Design Exception process provides
  an opportunity to fairly and objectively review
  and justify deviations
• My primary concern the public is driving our
  highways at ever increasing speeds

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Higher Speeds My Concerns

• Public appears to be very comfortable driving at
  speeds above 70 mph at 80 and even 90 mph
  even in heavy traffic
• This exceeds the Design Speed used for most
  existing highways
• Modern vehicles and tires appear capable of
  these higher speeds
• Modern suspensions mask some sensations of high
  speed
• Unfortunately, I am not sure driver skills are
  able to effectively deal with this high speed
  when something goes wrong (most of us are not
  NASCAR drivers)
• Maintaining high design standards is our best
  hedge against this tendency toward higher speeds