Work Zone Detection
Brian Kary and Terry Haukom - RTMC
Provide Delay Information To Motorists
Potential for Diversion
Perception Tracking Survey Results
Why Do It
Page 3Base = 602 unless otherwise noted
The Dieringer Research Group, Inc.Prepared for MnDOT, September 2012
Perception Tracking StudyWave XI: July-August 2012 Phone Survey
Travel Time Messages – Ratings & Comments
• Overall, drivers continue to consider displaying travel time information on overhead electronic signs to be a good idea. There is a significant increase in the
proportion of drivers who consider displaying travel time messages an “Excellent” idea.
2012N=602
2011N=600
# % # %
Top 4 Box 472 78% 487 81%
Excellent Idea (10) 269 45% 230 38%
9 42 7% 60 10%
8 107 18% 124 21%
7 54 9% 73 12%
6 19 3% 17 3%
5 53 9% 46 8%
4 9 2% 9 2%
3 8 1% 12 2%
2 12 2% 5 1%
Poor Idea (1) 10 2% 11 2%
Bottom 4 Box 39 7% 37 6%
Don’t Know 19 3% 13 2%
Q71d. How would you rate the idea of posting travel TIME information on overhead electronic signs as a tool to manage traffic?
Mean = 8.19 Mean = 8.12*Totals may not equal 100% due to rounding. Data noted with arrow is significantly lower or higher respectively than 2011 at the 95% confidence level.
All Drivers
N = Base # = Frequency
Page 4Base = 602 unless otherwise noted
The Dieringer Research Group, Inc.Prepared for MnDOT, September 2012
Perception Tracking StudyWave XI: July-August 2012 Phone Survey
Travel Time Messages - Actionability
*Totals may not equal 100% due to rounding. Data noted with arrow is significantly lower or higher respectively than 2011 at the 95% confidence level.
2012N=398
2011N=393
# % # %
Almost always 74 19% 54 14%
Sometimes 155 39% 183 47%
Rarely 125 31% 119 30%
Never 43 11% 35 9%
Don't Know 1 <1% 2 1%
Q71b. How often, if at all, do you take an ALTERNATE ROUTE because a travel time message on an overhead electronic message sign showed a longer time than your usual time for the trip?
58%
• Among those drivers who make a route decision based on a travel time message, nearly 6 in 10 chose to take an alternate route at least some of the time.
Have Made an Alternate Route Decision Based on Time Message Info
N = Base # = Frequency
Proven Method of Calculating Travel Times
Reduced Costs◦ Utilize existing 150+ DMS◦ Utilize detection outside of work zone
Currently have 400 miles of freeway instrumented with loop detection
Future detection will utilize more Wavetronics sensors which may allow detection within work zones
Traveler Information
Why Integrate with RTMC?
Traveler Information• Traffic Reports
• Travel Times Signs
Wavetronics Sensor
Camera Wireless Modem Solar Power
Detection Trailer
Travel Time ZoneDistance BetweenStations = ½ mile
Distance BetweenStations = ½ mile
Error Caused by Increased SpacingBetween 55 MPH and 5 MPH
Spacing Distance Time Error (Minutes)1/2 5.5
1 10.92 21.85 54.5
Included in Main Project – Lump Sum◦ I-35E – From CR 96 to I-35
$250,000◦ I-694 – From Hwy 61 to Hwy 5
$185,000
Separate Project◦ I-494 – From Hwy 100 to 34th Ave (SP 2785-392)
$262,300
Past Projects
Not enough lead time for integration
Lack of communications about traffic switches
Inadequate detection methods◦ Increased detection spacing◦ Probe data
Issues with Past Projects
Total Project Estimated Cost - $750,000
Provide one prototype trailer.
SP 0285-65 on I-694 from Hwy 252 to I-35W. ◦ Provide 16 trailers.
SP 1982-161 on I-35E from I-35 south split to Cliff Rd. ◦ Provide 8 trailers.
SP 2776-103 Hwy 169 River Bridge. ◦ Provide 18 trailers plus 3 PCMS.
SP 7080-51, 7080-50 on I-35 from District Border to I-35 south split. ◦ Provide 30 trailers which includes 3 w/ cameras plus 3 PCMS.
Metro Wide Project - SP 8825-465
Questions?Brian Kary
Freeway Operations [email protected]
Terry HaukomRTMC Design and Maintenance Supervisor