Most frequently asked questions about Radar Speed Signs

Why install a Radar Speed Sign in your community?

The main motivation for local authorities to install a Radar Speed Sign in their community is to make drivers aware of their speed, especially in areas where speeds are excessive.
In addition, there are other reasons for installing a Radar Speed Sign:

  • Responding to a specific request from residents.
  • To secure a specific black spot or dangerous area, especially around schools or school pick-up zones
  • To reduce the speed of motorists through education rather than repression
  • To collect traffic statistics (average and maximum speeds, number of vehicles, etc.) to implement specific action related to road safety or road improvements
  • A Radar Speed Sign also makes it possible to meet three major objectives:
  • Enforce speed limits in problem areas
  • Inform and influence the behavior of the road user. For example: when the speed radar displays “ATTENTION SCHOOL”, the motorist immediately becomes aware of the risk in the vicinity and adapts his speed.
  • Increased vigilance at the wheel by visual stimulation (the Radar Speed Sign is visible from a distance, flashing speed digits, display of an alert message)

How effective are Radar Speed Signs?

After the installation of a Radar Speed Sign, our customers have observed reductions in speed of more than 25%. The effectiveness is linked to the combination of two characteristics: the vehicle detection range and the visibility of the Radar Speed Sign.
The psychological effect that the Radar Speed Sign has on the behavior of motorists can be explained by two factors.
The first one is the preventive dimension. The dynamic speed display immediately catches the attention of the driver: This is generally the case for speeds under 10 mph over the speed limit: the offending drivers do not realize they are speeding because they do not have their “eyes on the speedometer” all the time. According to a study conducted in 2014 by Cerema, the decrease in violations is close to 50% when road users pass by a Radar Speed Sign.
For drivers who are aware of their dangerous driving, being confronted with their speed and the warning message reminds them that their speeding endangers the lives of others.
Also, making their speed visible to other road users (pedestrians, cyclists or motorists) contributes to the effectiveness of Radar Speed Signs.
The second reason is enforcement. A motorist who sees a Radar Speed Sign understands that the community has taken steps to reduce speeding. The possibility of encountering the police or a radar equipped with a camera in the area is perceived to be higher.

Is a Radar Speed Sign effective in the long term?

Yes, Radar Speed Signs remain effective in the long term.
The visual stimulation generated by the radar has a direct psychological effect on the motorist. What differentiates motorists is the reason that motivates them to slow down: civic-mindedness or “fear of the police”. According to a study conducted by the Cerema between 2012 and 2014: “Speeds return to their initial level when the Radar Speed Sign is removed”.
This long-term effectiveness is confirmed by our customers feedback, especially those who invest again several years after installing their first Radar Speed Sign (more than a third of our customers have re-ordered after having purchased an Evolis Radar Speed Sign).
To evaluate the effectiveness of a Radar Speed Sign in the long term, two types of drivers must be identified:

  • Regular users of the road on which the Radar Speed Sign is installed (local residents, etc.) are reminded every day if they are driving too fast. Unlike traditional static road signs which lose their impact over time, the Radar Speed Sign has a conscious effect (visual stimulation) and an unconscious effect (the psychological effect of being dangerous to oneself and to others because of the red speed digits and the warning message). Moreover, once in the habit of driving at a slower speed in a specific area, it is easier to maintain this habit with the help of the Radar Speed Sign and the visual reminder that the speed has been respected (speed digits in green/thankyou message).
  • Occasional users will be surprised when they see the Radar Speed Sign (psychological effect), even if it has been present long term.

According to another Cerema study, “There is no threshold effect, i.e. a duration beyond which the effect of the speed camera decreases”.

Against which types of speeding are Radar Speed Signs effective?

A Radar Speed Sign is effective against all types of speeding since the information displayed is adapted according to whether the speeding is less than 10 mph over the speed limit (speed in red together with the danger triangle + a SLOW DOWN warning message displayed) or greater than 10 mph over the speed limit (red danger triangle alone + a stronger DANGER warning message displayed).

Motorists speeding less than 10 mph over the speed limit do not necessarily know that they are driving too fast. The visual stimulation of the Radar Speed Sign will make them aware of this and encourage them to slow down.

Motorists speeding more than 10 mph over the speed limit generally know that they are driving too fast. In this case, the effect is mainly related to the fear of a nearby speed camera or police presence.

Which communities are installing Radar Speed Signs?

All local authorities can be asked to install Radar Speed Signs:
The main purchasers are communities with less than 5,000 inhabitants because they are most often confronted with speeding problems (close to motorways/by-passes etc). Radar Speed Signs can provide an ideal solution in terms of investment/result ratio.
More and more communities with speed limits of 30 mph want to give their citizens the means to respect these new limits by equipping themselves with Radar Speed Signs. Their presence is recognized as increasing overall awareness of speeding in urban areas.

What are the different possible uses of Radar Speed Signs?

Radar Speed Signs can be used in different ways to meet the specific needs of communities:
Permanent: The Radar Speed Sign is permanently installed on site. For example, a community that wishes to protect a school zone or to secure the entrance of the town. Generally installed on existing lampposts and powered by a solar panel or mains electricity.

Semi-Permanent: The Radar Speed Sign is moved from time to time (once per month for example) to secure several areas of the town or shared between several towns. Generally installed on existing lampposts and powered by a solar panel.
Ultra-mobile use: The Radar Speed Sign in this case is regularly moved or rotated (more than once per month) between various locations where speeding is a concern. Generally installed on existing lampposts and powered by 2 batteries.

Where to install a Radar Speed Sign?

Because of their versatility, Radar Speed Signs can be installed in all types of locations. Nevertheless, they are very often installed:

  • At the entrances to built-up areas: The Radar Speed Signs reminds users that they are passing from a road that was limited to 70 or 90 mph to a road that is limited to 50 mph.
  • Near schools: the device makes it possible to secure areas that are at risk because they are frequented by children. It is possible to set specific messages for specific times in order to increase the effectiveness of the radar.
  • Near a construction site: as is the case of schools, workers on the construction site can cross the road at any time. The Radar Speed Sign then becomes essential to alert road users of the potential hazard.
  • Upstream of an intersection: in order to avoid potential accidents or to secure an intersection that is known to be dangerous, the Radar Speed Sign is installed upstream of the intersection and can be useful for reminding people of the right of way (customized text massage), for example.
    Regardless of the area to be secured, the installation of a Radar Speed Sign requires some precautions:
  • It must be installed on the right side of the road (in the direction of traffic) and as far as possible perpendicular to the road axis
  • The Radar Speed Sign must be clearly visible and not interfere with the legibility of existing signage
  • the bottom of the Radar Speed Sign must be at least 2.20m from the ground (so as not to hinder pedestrians)

How does a Radar Speed Sign work?

To measure the speed of the oncoming vehicle, the Radar Speed Sign is equipped with a Doppler antenna.

This antenna emits magnetic waves at a certain frequency which are bounced back to the Radar Speed Sign by the first moving vehicle. These reflected waves come back at a slightly different frequency than those that were emitted (this is called the Doppler effect). It is thanks to this difference in frequency that the speed can be accurately calculated by the Radar Speed Sign.

This information is then relayed to the display of the Radar Speed Sign. The speed is calculated in real time, but it is only updated every second from the moment the vehicle is detected so it is easier for the road user to read.

Is the speed displayed accurate?

The accuracy of the speed displayed by a Radar Speed Sign is a combination between the accuracy of the antenna and the capacity of the digital speed display to update regularly. The speed display is therefore accurate and reliable when these two elements are achieved in the same Radar Speed Sign.

Our Radar Speed Signs are subjected to rigorous quality testing offering an accuracy of +/- 1%.

Will the Radar Speed Sign be well appreciated by road users and residents?

Yes, without a doubt! The Radar Speed Sign benefits from and a positive image among local residents and road users.

This image is reinforced by the fact that the Radar Speed Sign is installed so that road users become aware of their speed by themselves. It allows drivers to take responsibility without going through the “repression” stage.

Studies conducted by Cerema confirm this: for more than 90% of the people questioned said that the Radar Speed Sign is informative, preventive and educational. Thus, for the vast majority, the installation of a Radar Speed Sign is welcomed.

How to choose a Radar Speed Sign?

It is very simple: a Radar Speed Sign is effective when it reduces the speed of road users. The longer the user is aware of the Radar Speed Sign, the greater the speed reduction will be.

To choose an effective radar, it must therefore “see” far and be “seen ” from afar.

Thus, the range of detection and the quality of display (number of LED, brightness, contrast etc.) are the most important characteristics to be aware of when choosing a Radar Speed Sign

Not all Radar Speed Signs have the same performance in terms of detection range. Some will only be able to detect vehicles within 150m. Our Radar Speed Sign can detect vehicles from 300m.

In the same way not all displays are the same, some possess only one line of LEDs to display the speed. Our Radar Speed Sign displays the speed with three lines of LEDs, making it visible from further distances.

What are the different power options?

Given the different possible uses, the Radar Speed Sign can be powered in several ways:

  • Direct AC or public lighting: the internal batteries are recharged during periods when public lighting is on and allow the device to operate when the public lighting is off
  • By a solar panel: the batteries are recharged by a photovoltaic panel located above Radar Speed Sign
  • By internal batteries recharged manually with an external charger (similar to those used for car batteries)

Regardless of the power option chosen, the Radar Speed Sign functions in the same way. The different power options have more to do with the intended use of the Radar Speed Sign than its function.

How to avoid the “Race” effect?

When Radar Speed Signs first appeared, the speed displayed was not restricted and inadvertently caused the phenomena of racing or record chasing.

With the introduction of clearer regulations, Radar Speed Signs must now be equipped with an “anti-race” threshold. Thus, beyond a defined speed, the Radar Speed Sign displays a red “Danger” triangle and no longer displays the speed. (The red “Danger” triangle can be disactivated in which case the display will be blank.)

: + 10 mph over the limit in built-up areas and + 20 mph outside built-up areas

Can a Radar Speed Sign record traffic statistic?

Yes, thanks to its internal memory, our Radar Speed Sign can record traffic data that can then be used by the town hall or police. Using USB, Bluetooth or GPRS, the data collected by the Radar Speed Sign can be downloaded to a computer for analysis.

Average and maximum speeds, number of vehicles and the 85th percentiles are collected by the Radar Speed Sign for both directions of traffic to evaluate the behavior of road users.

The software allows this data to be exported (in pdf for example) so that it can be shared during a council meeting or distributed to citizens.

How do you install a Radar Speed Sign?

A Radar Speed Sign can be installed on various posts/poles. The type of power supply chosen generally determines the type of post/pole chosen.

In the case of solar power, the Radar Speed Sign is in most cases installed on a dedicated post/pole which is stabilized by a concrete foundation. This installation makes it possible to support the weight of the Radar Speed Sign and the solar panel.

In the case of AC or public lighting power, the Radar Speed Sign is generally installed on an existing post/pole (electric post or lamppost). The power supply is then taken directly from the grid.

In the case of battery only power, the radar is often installed on a tripod in order to be ultra-mobile or on existing pole/post. (mounting hardware can be pre-installed in various locations for easy rotation)

What is the average cost of installation?

The average cost of installation depends essentially on the type of power supply chosen:

  • In case of solar, the cost of the post and concrete foundation is between £500 and £1000.
  • In case of AC or City Lighting power, the installation of a 30mA circuit breaker and the connection varies between £200 and £600.

Can we install a Radar Speed Sign ourselves?

Our Radar Speed Signs are designed to be very easy to install.
Solar installations do not require any technical skills and can be installed by one person.
As for electrical installations, they are similar to connecting Christmas decorations.


How can I help calm motorist behaviour & how can I improve communications with the general public?

By drawing upon our experience in the manufacture of the Evolis, we can now complement our Radar Speed Sign with a new range of equally reliable & competitively priced products.

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