# Iowa's evaluation of the wizard cb alert system

# Ali Kamyab, Research Scientist

# Center for Transportation Research and Education

# Iowa State University

# Ames, Iowa 50010

# T. H. Maze

# Former Director of the Center for Transportation Research and Education

# Currently Vice President for Transportation Services

# Howard R. Green Company

# St. Paul, Minnesota 55108 

# Introduction

This paper reports on the evaluation of one technology intended to
manage vehicle speed in and around work zones on interstate highways.
The technology tested is the Wizard CB Alert System. Other technologies
were tested as part of an Iowa Department of Transportation (Iowa DOT)
sponsored evaluation of three technologies. The other two are reported
elsewhere. The Wizard CB Alert System is a device that continuously
broadcasts a warning message over Citizen Band radio warning approaching
drivers of the work zone ahead.

The Iowa DOT test is part of a Federal Highway Administration (FHWA)
pooled fund study involving the State Transportation Agencies in Iowa,
Kansas, Missouri, and Nebraska. The pooled fund study, called the
Midwest States Smart Work Zone Deployment Initiative (MwSWZDI). The goal
of the project is to develop better ways of controlling traffic through
work zones, which improves traffic safety and traffic operating
efficiency of work zones. To achieve this goal, the program is
evaluating or has evaluated a myriad of technologies for the management
and control of traffic through work zones. The Iowa DOT worked with the
Center for Transportation Research and Education (CTRE) on the
evaluation of technologies of interest to the Iowa DOT. CTRE evaluated
the Wizard CB Alert System (CB Wizard) during the summer of 1999. The
purpose of the evaluation was to determine if the CB Wizard could
successfully assist in controlling traffic along moving work zones on
interstate highways. The evaluations were largely subjective but very
positive results were achieved.

# 

# WIZARD CB ALERT SYSTEM

The Wizard Work Zone Alert and Information Radio was designed and
patented by Highway Technologies inc. and built and marketed by TRAFCON
Industries Inc. A picture of the device evaluated in Iowa is shown in
Figure 1. It is designed to give drivers monitoring the CB radio
advanced warning of upcoming delays at construction sites or incidents.
The advanced warning will allow drivers the opportunity to moderate
their speed and become observant of the need to slow, stop, or maneuver
before they reach the work zone or encounter queues of halted vehicles.
Since truck operators most commonly monitor CB radios, it was assumed
that the CB Wizard would have the most impact on truck drivers. On rural
Iowa interstate highways, large trucks are a significant portion of the
traffic volume (as much as a third) and, due to their size and weight,
their intrusion into the work zone is more dangerous than it is with
other vehicles. The system was developed at the request of the
Pennsylvania Department of Transportation.

In July 1999 the CB Wizard was used in conjunction with a work project
performed by an Iowa DOT striping crew on Interstate Highway 35. The
purpose of this field test was to determine if CB Wizard assists in
advanced warning of a lane closure for truck operators.

# 

# EVALUATION CASE STUDY

The painting crew consists of four to five vehicles spread out over
approximately one mile and traveling at 25 miles per hour (MPH). The
lead vehicle is the stripping truck and the trailing vehicle is a pickup
truck that carries a flashing sign that reads "CENTERLINE/EDGELINE
PAINTING AHEAD." The CB Wizard was placed in the trailing vehicle to
extend the CB signal as far upstream as possible to maximize the amount
of time between the warning message and approaching the rear most
vehicle.

The CB Wizard was set to broadcast a warning message on CB channel 19,
the most commonly used frequency by truck drivers. A 30-second interval
between broadcasts of the warning message was selected to ensure that
the message was broadcast frequently enough so that truckers would hear
the message at least once while approaching the work zone.

Figure 1, Wizard CB Alert System

![](media/image1.png)

# EVALUATION PROCEDURE

Since the purpose for using the technology was to alert drivers of the
approaching moving work zone we really had two issues to evaluate. The
first one was whether drivers were actually received the message and
secondly, was the message delivered effective in alerting drivers to the
approaching slow moving vehicles. The first issue deals with determining
what proportion of the truck drivers actually heard the warning. Because
we had no means to stop trucks on the Interstate and ask 100 percent of
the operators if they hear the warning, we chose to ask a sample of
truck operators that stopped at a rest stop down stream from the moving
work zone and assumed that the truck operators that stopped at the rest
stop were representative of the entire population. To determine how
effective the warning was, we decided to monitor the truck operator
comments over the CB radio and interview truck operators at the down
stream rest stop to determine their opinion regarding the advanced
warning system's message. We would have liked to have had an analytical
measure of the systems impacts on speed in and around the work zone, but
the movement in the work zone makes measuring the speed of approaching
vehicles difficult and costly.

To perform the evaluation, two people were used to collect data. One
person stayed with the CB Wizard in the tailing vehicle of the
interstate paint crew. This person monitored the CB radio, listening for
comments from truck operators regarding the CB wizard.

The CB Wizard was set to broadcast over CB channel 19, the frequency
truck operators most commonly monitor. An interval between broadcasts of
thirty seconds was selected to ensure that approaching truck operators
heard the message at least once. The message was not broadcast over a
second channel.

The content of the message transmitted greatly impacts the effectiveness
of the system. Over the course of the test, the message that was used to
warn truck drivers was altered based on the suggestions of truck
operators. The first variation of the message had the following content
and was read using a very official and authoritative voice:

"This is the Iowa DOT. Slow-moving paint operation in the right lane of
northbound Interstate 35. Please use caution."

The above message worked, but truck operators suggested that the
effectiveness of the message could be improved if a location for the
work zone was identified. The second variation of the message became:

> "This is the Iowa DOT. Slow-moving painting operation in the right
> lane of northbound Interstate 35 -- milepost 160 to milepost 170.
> Please use caution."

Although the second message was a little longer, it became much clearer.
Milepost ranges were normally announced in five to ten mile intervals.
The smaller the range, the more useful the message became. However, this
would mean more work for the operator to update the message more often.

In an attempt to reduce the amount of time spent on recording and
changing the CB message, the announcement was changed to give a relative
location rather than a specific location of the paint crew. The new
message became:

> "This the Iowa DOT. Northbound drivers on Interstate 35, you are
> approaching a slow-moving paint crew in the right lane. Please use
> caution."

This message was very successful. The only suggestions one truck
operator had was that some drivers might tune out the message once they
heard "Iowa DOT" thinking that the message might be from the Iowa DOT's
commercial vehicle enforcement officers. Therefore, the final message
was changed to:

> "This is an Iowa DOT road work alert. Northbound drivers on Interstate
> 35, you are approaching a slow-moving paint crew in the right lane.
> Please use caution."

The last message concisely presented all the pertinent information.
Also, the message would only need to be changed when the paint crew
changed direction or changed roadway.

**CB Radio Comments**

Most of the comments expressed by truck operators over the CB radio
related to the roadwork itself rather than the message. Many truck
operators expressed their disapproval of the time or location that work
was taking place. However, many truckers did notice that the CB message
was something new and different and the following are representative of
the positive and negative comments:

Positive Comments

-   \"That must be a recorded message.\"

-   \"Okey-dokey!\"

-   \"That\'s what I think all states ought to do - get on the CB and
    warn you about this stuff.\"

-   \"OK, thank you.\"

-   \"Thanks for the info. I appreciate that.\"

-   \"Thank you - and we will (use caution).\"

-   \"Allrighty!\"

-   \"Thank you, sir.\"

-   \"That\'s the first time I\'ve ever heard anything like that. I wish
    everyone would do that. It\'d make things a lot easier.\"

-   \"That was a recording. They must change the mile markers on that.\"

-   \"That\'s pretty good. I\'ve never heard that before. That\'s
    smart.\"

-   \"Thank you for that!\"

-   \"Hey, whoever says that on the radio, it sure saves a lot of
    hassle.\"

-   \"They ought to do a lot more of that.\"

-   \"Thank you all. I appreciate it. I\'ll see you up there.\"

-   \"That\'s a good idea.\"

-   \"I wish more states would start using the CB radio like this.\"

-   \"Yeah, that\'s the first time I\'ve heard something like that.\"

-   \"Throw a milepost in there and you\'d have it right.\"

Negative Comments

-   \"You\'ve got enough trucks and signs out there. You don\'t need to
    tell us this stuff every five seconds!\"

-   \"Get off my radio. You need to get on a regular radio station and
    warn those four wheelers.\"

**Rest Area Survey**

A data collector was located at a rest area upstream from the mobile
work zone and positioned in a location near the truck parking. The
individual stopped truck operators, identified himself/herself as data
collector for an Iowa DOT research project, and asked them if they would
answer a few questions. Most truck operators were willing to take the
time to answer our questions but some were not. For willing
participants, the interviewer had a few set questions. They were:

1.  How many years of professional driving experience do you have?

2.  Do you have a CB radio in your truck?

3.  Did you see the paint crew on the interstate and if so what alerted
    you first to the paint crew?

4.  Did you hear the CB announcement regarding the paint striping crew
    and on what channel?

5.  Did you think the message was an effective warning?

6.  Was the message obtrusive or annoying?

7.  This system may be used more often in the future. Do you think this
    would be helpful?

Over the course of six days, the interviewer was able to interview a
total of 94 truck operators. Of the drivers surveyed, 88 (94%) had a CB
radio in their truck. Of those, 70 (80%) had their radios tuned to
channel 19. Of these 70 truck operators, 59 of them (84%) saw the paint
crew on the interstate. Thus, 59 truck operators out of 94 (63%) had
their CB radios tuned to channel 19 as they passed the paint crew on the
interstate. The following are the results of what the 59 truck operators
that had their CB radio tuned to channel 19 and passed the paint crew
said alerted them first to the paint crew:

  ------------------------------------------ ------------- ---------------
  CB Alert Message                           24            (41%)

  Lights on Trucks                           14            (24%)

  Signs                                      10            (17%)

  Arrow Board                                7             (12%)

  Other Truck Drivers                        4             (7%)

  Total                                      59            (100%)
  ------------------------------------------ ------------- ---------------

Of the 59 Truck operators, 44 (75%) stated that they heard the CB Wizard
message, although it may have not been the first indication that they
were approaching the paint crew. Of the 44 truck operators that heard
the announcement, 39 (89%) thought the message effectively warned them
of the paint crew. When asked if the message was obtrusive or annoying,
43 of the 44 truck operators answer no. Finally, when asked if they
thought the system's use should be continued future, all 44 answered
yes.

The following are some of the comments truck drivers gave when asked
their opinion of the CB Wizard alert:

Positive Comments

-   \"If late at night, hearing something like this come on may help
    alert drivers.\"

-   \"Anything like this is helpful.\"

-   \"This could save accidents from happening.\"

-   \"It gives us better preparation - especially if coming up over a
    hill.\"

-   \"Cars notice when trucks move over. Hopefully it would prevent any
    rear-end collisions.\"

-   \"Neat idea! More states should use this!\"

-   \"Every little bit helps, but flashing signs alert the most.\"

-   \"This alerts everybody. It\'s a good idea.\"

-   \"You know what\'s going on ahead of time.\"

-   \"The paint crew is moving all the time. You never know where
    they\'ll be. It helps.\"

-   \"I loved it! I got into the left lane right away - over two miles
    before the paint crew.\"

-   \"It is a good idea. Police should use this for accidents. The paint
    crew was over a hill and I heard the message before I even saw
    them.\"

-   \"Other states should learn how to use this. I have also heard it on
    I-70 in Missouri.\"

-   \"No complaints. It worked really well. Everyone was merging.\"

-   \"It\'s great. It\'s good for those without radios, too, because if
    trucks slow down, cars will too.\"

-   \"It\'s a good idea if used right with useful information.\"

-   \"It is very effective because I heard it before I got to the paint
    crew.\"

-   \"If it helps save a life or prevent an accident, it\'s worth it. I
    liked how clear it was. Great idea.\"

-   \"It doesn\'t hurt anything.\"

-   \"The CB is used for communication. Any time you have advanced
    warning, it\'s helpful.\"

-   \"It seems to work well in Missouri where they use it a lot.\"

-   \"Advanced notice is the ideal.\"

-   \"Good idea. This kind of thing is the only reason I listen to the
    radio.\"

-   \"I knew it was a recording, so I thought it must be important. It
    made me listen and be aware of the situation.\"

-   \"I argued with another guy who thought it was a joke. It is a very
    good idea.\"

-   \"It\'s definitely helpful at alerting drivers. They should use it
    at all construction zones and have state troopers there to slow down
    four-wheelers.\"

-   \"A good idea, but sooner (warning) would help.\"

-   \"You know what\'s going on before you get there. You should notify
    truckers even sooner.\"

-   \"The message wasn\'t loud enough. It\'d be more effective if
    drivers going the other way would warn truckers.\"

-   \"Make it louder or more powerful. Also use it in construction zones
    and for snow removal.\"

Negative Comments

-   \"Use caution? How do you use caution?\"

-   \"Are truckers the only dumb ones that need to be warned? You need
    to warn cars, too.\"

**Conclusions**

Our evaluation of the Wizard CB Alert System resulted in very positive
findings. We found that the device was effective in warning truck
operators of approaching mobile work zones. Sixty- three percent of the
truck operators that had their CB radio tuned to channel 19 as they
passed the paint crew heard the Wizard CB Alert message and 41 percent
stated that the CB message was their first indication that they were
approaching the paint crew. The system reached a large portion of the
target audience and passed on information that was important to its
listeners. Many truck operators voiced their approval for the system,
showing their support for its continued use in the future, and even
suggesting additional situations where the system would be helpful.

# Acknowledgements

We would like to thank the Office of Traffic and Safety at the Iowa DOT
for their support of this project and Midwest States Smart Work Zone
Deployment Initiative FHWA pool funded study for their institutional
support. The Midwest State Smart Work Zone Deployment Initiative's home
is at the Mid-America Transportation Center at the University of
Nebraska -- Lincoln.