The phone rings. The city manager is getting complaints about speeding in three different neighborhoods. “What can you do about it?” he asks. The school superintendent wants to know how to slow drivers down in the school zones. He says, “We almost had two kids hit last Friday by speeders!” Next to driving under the influence, speeding is the second leading cause of accidents/fatalities in your town and the nation. (Source: Traffic Facts – U.S.D.O.T.). You can’t put an officer on every street corner. You barely have enough to man the cars now. You call your traffic sergeant and say, “Sarge, I want you to research and make recommendations on radar trailers and radar displays. Have it ready for the city council meeting in three weeks. Include prices, warranties, and any research on their effectiveness.” Sarge says, “Yes, Sir,” then turns his head away with a puzzled look. Decisions in any community are a consensus of an opinion – everybody’s got one and many times that’s the problem. Opinions are based on assumptions and not facts. If you recommend the wrong answer, you get the heat! What will Sarge do? Selecting the right radar trailer or radar display can be the best public relations a department can get; selecting the wrong equipment can be the worst!

Sarge Doing Research on Effectiveness

There is almost a total void of radar trailer and radar display effectiveness research on the Internet and elsewhere. If you call radar trailer and radar display representatives, they all say theirs is the best, but where is the documentation? In April 1997, the San Diego County Sheriff’s Department found a Kustom Signal’s radar trailer to be extremely effective. Before placement of the trailer, 77% of the drivers exceeded the school zone’s 20 mph limit. After placement, only 20% of drivers exceeded the limit. Speed Measurement Laboratories, Inc. (SML) found that Applied Concepts, Inc. (i.e., Stalker) radar trailers, placed in El Paso and Del Rio, TX, school zones produced sustained, long-term speed reductions and improved speed limit compliance (“Radar Trailer Effectiveness in School Zones,” Law and Order Magazine, August 2000). Before trailer placement in Del Rio, 81% of drivers exceeded the limit. After that, only 18% were above the limit. El Paso data were almost identical with a significant speed reduction of 8.5 mph, 85th percentile with the trailer in place.

Texas A & M University’s Texas Transportation Institute (Report #00-1475) found that large numeral LED radar displays to be “statistically significant” in reducing speeds. The report attributes the effectiveness to visibility of the displayed speed numerals.

The University of Kansas’ Dr. Eric Meyer related, “The radar display was quite effective, reducing mean speeds, 85th percentile speeds, and the percent of drivers exceeding the posted limit.” Dr. Geza Pesti, Department of Civil Engineering, University of Nebraska, conducted a long-term study on large digit, LED numeral speed displays. He found the “percentage of passenger and nonpassenger cars complying with the speed limit increased to 91 and 90 percent respectively” with the use of high visibility speed displays. He also found “it was equally effective day and night, with even greater effectiveness at night because of its greater nighttime visibility.”

The city of Phoenix compared the effectiveness of speed displays from 3M and Applied Concepts, Inc. in two different school zones. At the Greenway Road location with the Applied Concepts display, the 85th percentile was reduced from 47-48 mph to 14-16 mph with the radar display in operation in the 15 mph school zone. At the 19th Avenue location with the 3M display, 85th percentile speeds were reduced from 32 mph to 25 mph, after the 3M display was operational.

SML conducted long-term radar display, not trailer, research in three Texas communities – Marshall, Del Rio, and El Paso – to see if the speed reductions would fade with time. This is called a “halo effect.” There’s always someone who flatly claims, without research, “They may work the first week you put them up, but, after some time, people will disregard them.” SML found one day after installing speed displays that Marshall had a school zone speed limit compliance rate of 69%; El Paso was at 72%. One month after placement, The Marshall Messenger (November 29, 2000) reported 73% compliance and the El Paso Times (August 18, 2000) confirmed 73% compliance. These data clearly show long-term effectiveness. The Taos News (New Mexico) reported (January 24-30, 2002) that before a speed display was placed in a problem neighborhood, only 13% obeyed the 30 mph speed limit. After placing a pole mounted speed display, 86% respected the speed limit. Houston’s El Dia newspaper conveyed similar results. In their January 24, 2002, issue, El Dia related only 10% of vehicles were driving the 20 mph school zone limit before placement of a pole speed display. Afterwards, the compliance rate rose to 85%.

Visibility

In order to be effective, radar displays must be seen – all the research confirms this. Visibility is the most important feature of any radar display. You wouldn’t buy a bullet-resistant vest which didn’t stop bullets because it was “low bid.” Why buy a radar trailer or display which drivers can’t see?  With few exceptions, do not consider anything smaller than 14" high numerals; they must be high intensity LEDs.

Keep in mind that the faster the traffic is traveling, the larger the display must be for motorists to see the display and respond to it. In instances when federal money is being used to purchase equipment, the radar display must comply with MUTCD (Manual on Uniform Traffic Control Devices) regulations, ie., the numerals must be either lime green or yellow and the case should be white – not red or amber! However, many aspects of the MUTCD are open to interpretation and vary according to the type of system. The federal government has long promised clarification regarding radar displays. Presently, U.S.D.O.T. does not issue letters of compliance to any vendor of trailers or displays and the final clarification looks years away. Find out if the system you are considering fits the guidelines of your city and state traffic control regulations. If you use local money, it’s your call.

Before purchasing a radar trailer or radar display, ask that the vendor demonstrate it to you at no charge and, whenever possible, leave you a sample for at least a week! Make sure the vendor has local representation and warranty service. You can’t UPS a 1,500 pound radar trailer for warranty service; however, on certain models, only the module needing repairs has to be returned to the manufacturer, not the whole unit. When one large metropolitan police department had a problem with their radar trailer, the vendor said they would service it if the department drove it to their plant – 600 miles away. One year later, the trailer is still inoperable and sits rusting in the property yard.

Accuracy

One western Texas community thought they had a deal on a radar trailer. They bought it sight unseen. When on the street, drivers couldn’t see their speed until they were 50 feet from the trailer and it displayed the wrong speed. The phone calls started coming to City Hall and the vendor said it was “their problem.” They put on two amber beacons to draw attention to their radar speed trailer which still didn’t show the correct speed! Next to visibility, correct speed reporting is critical to effectiveness. If it shows the wrong speed, drivers will disregard your investment. Many communities and states can tell horror stories about radar displays/trailers which consistently show the incorrect speed.

Buy a trailer or speed display which only does one thing: shows speed and not speed and messages. By the time the message is displayed, 50 other vehicles have passed. Stop signs and speed limit signs show only one thing and do not include an “Eat at Joe’s” message.

It’s best to invest in current direction sensing radar technology. Direction sensing means the radar will only show the speeds of approaching vehicles. You want approaching drivers to see their speed and not the 18-wheeler going away. Do not use X-band radar trailers/displays. Fifteen percent (15%) of drivers own a radar detector. They disregard X-band warnings as false alerts coming from supermarket automatic door openers, burglar alarms, and other sources.  K- and Ka-bands are essentially devoid of such false alerts.

If you are using the radar equipment for law enforcement activities, such as issuing speeding tickets, your equipment should meet the criteria of the IACP (International Association of Chiefs of Police) and be included on their Consumer Products List (CPL). See www.theiacp.org/profassist/radar.htm for a listing of I.A.C.P. approved radar. Several Ontario police agencies were embarrassed when Ontario Provincial Police told them they couldn’t use non-I.A.C.P. approved radar guns they had just purchased. Look at trailers and displays from radar gun manufacturers before looking at others. They can offer the best nationwide warranty service and local representatives. Watch out for the guy with a welding torch and a garage, although some well-known manufacturers may have started out that way. Whatever you do, get referrals from vendors and call them!

Radar Trailers or Radar Displays, Sarge?

Sarge knows both radar trailers and radar displays are effective, but which one to buy? Radar trailers seem like a good choice because you can tow them around. They are three times the cost of radar displays, but mobility is important. Wait a minute, Sarge! Let’s look at experience talking. First, is it legal to operate radar trailers/displays? Drone Radar Operational Guidelines (U.S.D.O.T. HS #807 753) allows the legal operation of radar trailers/ displays. You also have an implied RS Radiolocation CFR 47 license to operate radar as part of your commercial police radio license. Although radar trailers seem to be flexible, sometimes, they’re not. You have to dedicate one unit to transport and maintain the trailers. Many times, where you want to place it doesn’t allow enough space. They are heavy and cumbersome! If you have only one trailer, everybody wants to use it.

Powering is the big headache with trailers. They are powered by batteries or with a solar assist. Although some solar assisted units can be fully independent when used in places such as Florida or Arizona, most solar panels can not independently power a radar trailer.

The amount of power needed ultimately depends on the requirements of the unit itself; some simply need more power than others. In most models, you must recharge the batteries at regular intervals. If you forget, you’re out of juice. After the initial excitement of getting a radar trailer, usage normally wanes because of powering and cumbersomeness. If it breaks, how do you get it fixed? It’s not like your Crown Vic with a nearby Ford dealer.

Radar Displays

Radar displays are becoming an attractive, flexible alternative to radar trailers. For the price of one radar trailer, you can buy three to four radar displays. Many speed displays can be powered by either AC or DC automatically. They can be mounted on exiting AC poles, completely powered by a solar panel/battery combination or powered by a police vehicle.

One of the best applications comes from Blaine, Minnesota. Lt. J.M. Miller reports great success with the five Olsen Engineering speed displays used by the city. Blaine erected 46 poles at 23 locations throughout the city where community speeding was a problem. The speed displays are rotated among them on a regular basis. They are powered by two batteries. Lt. Miller reports, “Citizens have been very positive about the speed displays. When we rotate them from pole to pole, homeowners come out and plead with us to leave them where they are in front of their house. Speed reductions have been substantial. We intend to buy more. We have used them for a year and have had one incidence of vandalism.”

Chief Lanny Maddox, Ruidoso, New Mexico, Police Department, installed two Precision Solar Controls speed displays in the town’s shopping district in 1996. Chief Maddox related, “It’s probably the best investment I ever made. Speed limit compliance is approximately 97%. People don’t realize how fast they’re going and the radar displays get their attention. With the solar panel continually charging the batteries, we have never had an electric bill. I am recommending to the council that we buy more.”

Sheriff Arvin West, Hudspeth County, TX, oversees law enforcement in a county measuring 5,780 square miles. The county is dotted by many small communities.  The county seat of Sierra Blanca has the last all adobe courthouse left in the nation and 800 citizens. Hudspeth County is enormous, wide open spaces dissected by Interstate 10 which results in a serious speeding problem. In August of 2001, the county saw 15 traffic deaths. Sheriff West says, “One out of every three cars in our school zones was speeding. We have limited resources and needed a truly portable speed display we could easily move around. We bought an Applied Concepts, Inc. speed display. We attach it to existing school zone poles and also on our patrol cars. We even use a DOT stand with batteries. It has greatly reduced speeds.” County Commissioner Pilar C. Ortega echoes Sheriff West’s comments. Commissioner Ortega states, “The people love it. It multiplies our law enforcement efforts and placing it in one of our school zones is just like having an officer there. I have not had one negative comment from any citizen.” Some communities have initiated the tax deductible “Adopt a School Zone” program soliciting funds from companies, individuals, and organizations to pay for the speed display. This is much like the popular “Adopt a Highway” system. Donors have their names attached to poles next to speed displays.

Field experience tells us that speed displays should have several capabilities. They should offer a 24/7/365 timer when used in school zones. This allows operation only when school is in session. The radar’s reporting range should be adjustable. It serves no purpose to have radar report a speed from one mile away or a vehicle located in an adjacent shopping center parking lot. It should report speeds as drivers enter school zones or other controlled locations. The narrower the radar beam, the better. Ka-band has the narrowest beam, while X-band is immense!

Some speed displays have a flashing strobe and flashing numerals when an approaching vehicle exceeds the speed limit. When the vehicle comes into compliance, the flashing stops. This is called “Violation Alert” and is a proven feature. Speed displays should have “Maximum Speed Cutoff.”  When set at 80 mph, the speed display will not show speeds above the setting. If desired, speed displays should show approaching vehicle speeds while attached to a moving patrol car.

What About Statistics, Sarge?

The chief wants traffic statistics and many advertised radar trailers and speed displays offer the feature. What should Sarge know? Using radar to compute traffic statistics is like trying to count fish in a muddy lake – you will see a few, but miss most. Radar is the worst way to get numbers! Radar can’t discriminate among vehicles and always seeks the most reflective target. You see the 18-wheeler, but miss the ten other vehicles in the group. If you use radar for statistics, you are alerting the 15% of drivers using a radar detector and they slow down. Radar and road tubes/road sensors can’t compensate for “platooning” of vehicles and don’t know that the long line of cars which just passed was a funeral procession. Accurate traffic statistics come from measuring “free-flowing” vehicles, not those whose normal speed is impeded by others. A radar statistical package will give you numbers to present to the city council, but they will be wildly wrong! Radar-based statistical programs give you “drive thru” convenience while sacrificing any approach to accuracy.

Due to limitations of radar and road tube/road sensor systems, the nation’s major universities use laser-based measurement systems for accurate numbers. The laser gun must be held by a human being. Kustom Signals Inc.’s new Laser Cam II system automatically transfers target vehicle speeds to a laptop statistical program while recording a digital image via an Olympus camera. Laser Technologies Inc. (LTI) also offers a convenient laser-based system. Laser is vastly superior in obtaining accurate traffic statistics and can pinpoint one vehicle in a group without alerting detectors.

Conducting Your Own Test and Your Checklist

Sarge, before you make a recommendation, conduct your own effectiveness test. Here’s what you need to do. If possible, have each speed display vendor provide a sample for a week. Mount the display on a pole and get your video camera. The most important feature of any speed display is visibility. Visibility is effectiveness. Stand hidden down the street and watch where the oncoming vehicles consistently hit their brakes and place a cone there. This tells you where they reacted to the speed display. Measure the distance to the cone from the speed display. Go back to your hiding place and record video of the vehicles approaching the speed display. Talk into the recorder as they brake and relate the distance and any emergency braking you see. Do this for each sample. To be safe and effective, you should see the brakes being applied no less than 600 feet from the speed display. Take your tapes and show all of them to the chief. Also, videotape each speed display in direct sunlight. Many times, direct sunlight will wash out speed readings.

Sarge has decided! With his budget, he will recommend one radar trailer and three speed displays. His homework and research will reward the department and community with speeds which can be controlled.

For more information, contact:

About the Author: Carl Fors, President,  Speed Measurement Laboratories, Inc.,  has over 16 years of radar/laser experience. He has instructed at IPTM and speaks with regularity to police organizations. He has appeared on “The Learning Channel”; “The Discovery Channel”; “CBS News”; “Inside Edition”; and is continually published on related issues.  He may be reached by E-mail at speedy3@speedlabs.com, or visit SML’s Web site at www.speedlabs.com.