I4 VARIABLE SPEED LIMITS: A SMARTER PACE

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I-4 VARIABLE SPEED LIMITSA SMARTER PACE
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WHAT ARE VARIABLE SPEED LIMITS?

• Tool for managing I-4 congestion
• FDOT monitors roadway conditions and reduces I-4
  speed limits accordingly
• Orlando is the most congested city in Florida and
  the 9th most congested city in the nation.
• Source  Texas Transportation Institute 2005
  Urban Mobility report

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WHAT AREAS WILL BE AFFECTED?

• 10 miles on I-4 from Orange Blossom Trail to
  Maitland Blvd.(Both Directions)
• Central Business District of Orlando
• Kickoff September 15, 2008

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CAUSES OF CONGESTION
ROADWAY CONSTRUCTION
AUTO ACCIDENTS
EMERGENCY VEHICLES
WEATHER CONDITIONS
DISTRACTED DRIVERS
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CONGESTION VARIABLE SPEED LIMITS

• Congestion occurs when the roadway experiences
  more vehicles than it was designed to handle.

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WHY HAVE VARIABLE SPEED LIMITS?

• Immediate benefits include
• Reduced Congestion
• Fewer Accordion Effect Occurrences
• Improved overall safety
• Over time, motorists will see
• Improved gas mileage and less vehicle emissions
• Reduced commuting time
• Fewer crashes
• Improved travel time reliability

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THE ACCORDION EFFECT

• When drivers encounter traffic, they brake or
  accelerate suddenly
• Drivers behind them do the same

This stop-and-go traffic pattern produces the
Accordion Effect
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I-4 AT LIVINGSTON BEFORE IMPLEMENTATION

• Current Conditions (Rush Hour)
• Posted Speed 50 MPH
• Average Speed 30 MPH

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I-4 AT LIVINGSTON AFTER IMPLEMENTATION

• Smarter Pace
• Posted Speed 40 MPH
• Average Speed 40 MPH (Approx.)

MORE VEHICLES IN LESS TIME
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MANAGING CONGESTION
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I-4 ORLANDO

• Four Groups
• Eastbound South
• Eastbound North
• Westbound North
• Westbound South
• Four Sections per Group
• Based on
• Occupancy
• Speed
• Volume

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EASTBOUND NORTH GROUP

• Signs 10, 8, 6, and 2/4
• SR 50 to SR 414

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VSL 6

• Lee Road and East of Lee Road detectors
• Eastbound North Group

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VSL 6 40 MPH

• 50 mph to 40 mph when occupancy rate exceeds 15
• 40 mph to 50 mph when occupancy rate 12 or less

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Eastbound South

• VSL 18/20, 16, 14 and 12
• Afternoon congestion

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VSL 16 30 mph

• 40 mph to 30 mph when occupancy exceeds 28
• 30 mph to 40 mph when occupancy less than 25

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OPERATOR SCREENS

• Status of posted speed limits at all times
• Recommended plans require operator approval
• Changes entire group with approval

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WILL THIS SYSTEM BE SUCCESSFUL?

• Is Orlando ready?
• Success of Variable Speed Limits depends on the
  traveling publics reaction to the system.
• When all drivers comply with posted speeds, the
  number of vehicles that can safely use the
  roadway will increase and traveling I-4 will be
  faster and more efficient.

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WILL THIS SYSTEM BE SUCCESSFUL?

• Drivers need to change specific behavioral
  patterns and comply with posted speeds.
• If drivers ignore the posted speed limit and
  drive as fast as they can, the accordion effect
  will continue and drivers will still encounter
  congestion.

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CONVINCING THE PUBLIC

• Media Events
• Open House at Orlando Science Center
• Live interviews at RTMC

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CONVINCING THE PUBLIC

• Roadside Announcements
• Highway Advisory Radio
• DMS Alerts

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FOR MORE INFORMATION

• THANK YOU!
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• Rick Morrow
• Traffic Operations EngineerFDOT District Five
• www.trans4mation.org