Work Zone Mobility and Safety Program
Photo collage: temporary lane closure, road marking installation, cone with mounted warning light, and drum separated work zones.
Office of Operations 21st Century Operations Using 21st Century Technologies

Text from 'Smart Work Zone Systems' PowerPoint Presentation

Slide 1

Smart Work Zone Systems

Presented by

Prahlad D. Pant, Ph.D.

PDP Associates Inc.

Slide 2

Problems in Work Zones

  • Congestion and lack of real-time information
  • Safety of motorists and workers

Slide 3

Long Delay Ahead

Construction Ahead

Expect Delays

Slide 4

A "smart work zone system" is the application of computers, communications, and sensor technology to freeway transportation.

Slide 5

General Characteristics of Smart Work Zone Systems:

  1. Real-time:
    Analyzes traffic flow-data in real-time, providing frequently updated information to the motorists
  2. Portable
    Can be installed at different locations with minimal modifications

Slide 6

  1. Automated
    Operates in automated manner (24 hrs/day, 7 days/week) with minimal supervision by human operators
  2. Reliable
    Provides accurate and reliable information, taking into account the serious negative consequences of misinforming motorists

Slide 7

A smart work zone system, if properly designed and implemented, will:

  • Better inform motorists and reduce their frustrations;
  • Encourage motorists to take alternate routes;
  • Reduce congestion and allow more freely flowing traffic;

Slide 8

  • Clear incidents more quickly, thereby reducing secondary incidents;
  • Make work zones safer for highway workers and motorists.

Slide 9

Company Name System Name
PDP Associates TIPS and ASIS
ADDCO SmartZone
Nat. Intelligent Traffic Sys. ITS Workzone
Scientex ADAPTIR
United Rental AIMS

Disclaimer: The above list is provided for information only. The presenter is not familiar with the working or suitability of these systems except TIPS and ASIS.

Slide 10

Tips Logo

Traffic Information & Prediction System

Slide 11

Primary Objective

To provide travel-time information to motorists in advance of and through freeway work zones on a real-time basis.

Slide 12

A portable freeway traffic management system that can provide real-time, automated, accurate and reliable travel time information in advance of and through the work zone

Slide 13

Major Components

  • Software with intelligent algorithm and travel-time estimation models, based on sound traffic flow theory
  • Radio communication devices
  • Traffic sensors and microcontrollers
  • Mobile trailers with solar panels & batteries
  • Portable changeable message signs

Slide 14

Deployment in 2000:

  • I-75 work zone in Dayton, Ohio
    • Urban (Downtown)
    • Work zone - 3 miles
    • Advance area - 11 miles
  • July - November, 2000

Slide 15

Deployments in 2001

  1. I-75 Dayton, Ohio (April - Sept)
    • Urban (Downtown)
    • Work Zone - 3 miles
    • Advance area - 11 miles
  2. I-94 Milwaukee, Wisconsin (June - Oct)
    • Semi-rural
    • Work Zone - 12 miles
    • Advance area - 7 miles

Slide 16

Photo of traffic on a highway

Slide 17

Photo of solar panels at a work zone

Slide 19

Photo of solar panels at a work zone

Slide 20

Photo of a trailer

Slide 21

Computer displaying workzone data

Slide 22

Base Station:

  • Polls each sensor at 30-sec intervals and receives traffic flow data for each lane\
  • Calculates travel times and sends instruction to changeable message signs
  • Changeable message sign displays the message and sends confirmation to the Base Station.

Slide 23

Sign reading '44 minutes to end of workzone'

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Sign reading '40 minutes to end of workzone'

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Sign reading '20 minutes to end of workzone'

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Incident Management

  • Telephone dial-up and remote control of the entire system from anywhere
  • Capability to remotely and instantly display customized messages on any sign during incidents, temporary closures, or any unexpected conditions on the freeway

Slide 27

Sign reading 'Accident Ahead'

Slide 28

Sign reading 'Highway Closed Ahead'

Slide 29

Sign reading 'Highway Closed at Route 23

Slide 30

Independent Evaluation of TIPS

Performed for the Ohio Department of Transportation


Ohio University, Athens, OH

Final Report, March, 2001

Slide 31

Results of Independent Evaluation for Ohio DOT

  1. "About 88% of the actual times for each sign, and for all the signs combined, were within a range of plus or minus 4 minutes of the predicted times."

Slide 32

Time Difference Data for All Three CMSs Combined

Minutes Off Frequency Percentage
0 49 14%
1 117 33%
2 75 21%
3 51 14%
4 20 6%
5-8 17 5%
>8 26 7%
TOTAL 355 100%

Slide 33

Results of Independent Evaluation for Ohio DOT

2. "Almost 97% of surveyed motorists felt that a system to provide real-time travel time information in advance of work zones is either outright helpful or maybe helpful."

Slide 34

Question: Do you think that such a travel time prediction system in advance of work zones and in advance of exits in heavily traveled freeways where drivers could select an alternate route in situations where long travel times to the end of the work zone are predicted is helpful to the motoring public?

Pie Chart- Depicts the results of the question posed above. 85% said yes, it would be helpful. 3% said no, it would not be helpful. 11% said it may be helpful and 1% had no response.

Slide 35

Conclusions of Independent Evaluation of TIPS for Ohio DOT

"The real-time TIPS system represents a definite improvement over any static non-real-time display system".


Slide 36

Conclusions of Independent Evaluation for Ohio DOT

"TIPS provides in general and most of the time useful and relatively accurate travel time predictions to the motoring public and appears to be perceived by the motoring public as helpful and useful".

Slide 37

Independent Evaluation of TIPS

Performed for the "Midwest Smart Work Zone Deployment Initiative"

Iowa, Kansas, Missouri, Nebraska and Wisconsin


University of Wisconsin, Milwaukee, WI Marquette University, Milwaukee, WI

Interim Report, May, 2002

Slide 38

Independent Evaluation of TIPS Performed for the "Midwest Smart Work Zone Deployment Initiative" (Iowa, Kansas, Missouri, Nebraska and Wisconsin)

"The before and after analysis supports the notion that TIPS is influencing drivers to change their routes".

On Sunday afternoons, 10 percent of I-94 drivers chose an alternative route.

(Note: TIPS was not set up to provide any information on the availability of alternative routes.)

Slide 39

Independent Evaluation of TIPS Performed for the "Midwest Smart Work Zone Deployment Initiative" (Iowa, Kansas, Missouri, Nebraska and Wisconsin)

More results are expected to be available in the coming weeks/months.

Slide 40

Asis logo

Advance Speed Information System

Slide 41


To determine vehicular speeds at downstream segments of a freeway and display them on changeable message signs at upstream locations

Slide 42


ASIS is expected to reduce rear-end crashes by allowing motorists to adjust their speeds and reduce the elements of "surprise".

Slide 43

An "ASIS Sign" consists of a portable changeable message sign with the following equipment mounted on it and integrated as one device:

  • Traffic sensor
  • Microcontroller
  • Radio, modem and antenna

Slide 44

  • Two signs work in pair and any number of signs can be added as necessary.
  • Minimum no. of signs = 2
    Maximum no. of signs = No limit
  • Signs communicate with each other. A "base station" PC is not required. However, a "base station" is available as an option.

Slide 45

Map with traffic signs noted along a major highway

Slide 46

Consider the following scenario:

Line graph showing a scenario in which traffic traveling at 60mph slows to 30mph, 10mph, comes to a halt, and then increases speed to 25mph and 55mph all within the distance of one mile.

Slide 47

Sign reading 'Speed Ahead 30 MPH'

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Sign reading 'Speed Ahead 10 MPH'

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Sign reading 'Stopped Traffic Ahead'

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Sign reading 'Speed Ahead 25 MPH'

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Sign reading 'Speed Ahead 55 MPH'

Slide 52

TIPS and ASIS can use any changeable message signs specified by DOT.

  • Company provides communication protocols to the sign manufacturer.

Slide 53

A Few More Examples

Slide 54

Sign reading '30 Minute Delay Ahead'

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Sign reading 'Heavy Delay Ahead'

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Sign reading '1 Hour Delay'

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Sign reading '1 Hour Delay Ahead'

Slide 58


  • Provide a website with real-time travel time information
  • Provide real-time travel time information in rest areas, truck stops, office complexes, large traffic generators etc.

Slide 59

Options (contd.)

  • Provide video cameras for bringing live pictures of the freeway traffic to the project office and to the internet
    • Fixed cameras
    • Pan/Tilt/Zoom cameras

Slide 60

Options (contd.)

  • Provide Highway Advisory Radio
    • Old technology
    • Low usage by public
    • Potentially beneficial during incidents or special circumstances

Slide 61

Options (contd.)

  • For historical record, save and archive traffic flow and message data with time stamps for each sensor and each changeable message sign.

Slide 62

24-Hours Hot Line:
Toll free: 800-769-3839

Maintenance is provided 24 hours/day, 7 days/week.

Slide 63

Thank you.

Office of Operations