Driveway Profile Discussion Karl Oberjohn Infrastructure Committee - - PowerPoint PPT Presentation

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Driveway Profile Discussion Karl Oberjohn Infrastructure Committee - - PowerPoint PPT Presentation

Apr 20, 2023 149 likes •318 views

Lower Jackson Road Driveway Profile Discussion Karl Oberjohn Infrastructure Committee 9/10/2018 Can existing sidewalk be preserved? Benefits Maintain a grass strip between sidewalk and street Save money by only replacing damaged

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Lower Jackson Road Driveway Profile Discussion

Karl Oberjohn Infrastructure Committee 9/10/2018

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Can existing sidewalk be preserved?

  • Benefits

– Maintain a grass strip between sidewalk and street – Save money by only replacing damaged sections of sidewalk

  • Challenges

– New street will be 2 feet wider on each side due to addition of curbs and gutters – New street will shift location to help blend with existing driveways and facilitate proper storm water drainage

  • Street centerline will shift 1 foot north (toward even side)
  • Street elevation will drop by as much as 1 foot
  • Net result

– Driveway aprons would have to be steeper to meet the existing sidewalk

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Constant Slope

No vehicle clearance concerns with a constant slope

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Variable Slope – “Sag”

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Variable Slope – “Crest”

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Design Vehicle

Ground clearance affected by:

  • Passenger/cargo load
  • Tire inflation
  • Suspension
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Vehicle Clearances

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Sample Ground Clearances

Vehicle Ground Clearance (in.) 2018 Honda Fit 5.0 2019 Toyota Yaris 5.2 2018 Hyundai Sonata 5.3 2013 BMW 3-Series 5.5 2019 VW Jetta 5.6 2018 Toyota Camry 5.7 2017 Honda Accord 5.8 2016 Ford Fusion 5.9 2018 Toyota RAV4 6.5 2014 Nissan Rogue 7.4 2017 Honda CR-V 8.7 2018 Subaru Forester 8.7 2014 Jeep Wrangler 8.8

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Roll Curb Profile

For comparison, a box curb with curb cut has a 2 inch step up to the driveway

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Uphill Driveway

Current street design

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Uphill Driveway

Street elevation drops 9 inches

New street design

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Downhill Driveway

Current street design

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Downhill Driveway

Street elevation drops 12 inches

New street design

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Can existing sidewalk be preserved?

  • Analysis

– 9 driveways on north (even) side of street

  • 3 driveways will definitely experience vehicle dragging

if existing sidewalk is kept in place

  • 5 driveways will narrowly miss a drag condition,

depending on vehicle size, loading, and speed

  • 1 driveway will not be affected
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Sidewalk Placement Options

  • 1. Proposed: New sidewalk directly against curb
  • 2. Investigating: New sidewalk 4 feet from curb

– City Engineer’s office is evaluating this option – New sidewalk would be in same location as existing sidewalk, but at a different elevation – May require box curbs with curb cuts to keep slope transitions manageable – More-extensive restoration required for driveways and stone walls

  • Street trees will be lost in either case