Frequently asked questions

Why should I install a radar speed sign in my area?

The main reason for authorities to install a radar speed sign in their area is to educate drivers about the speed at which they drive, especially where this speeds seems to high compaired to speed limit.

Furthermore, other motivations lead communities to install a radar speed sign:

  • Answer a specific request of residents who feel a lack of road safety
  • Securing a specific location by anticipating potential accidents, especially near schools and school bus places
  • Lowering the speed of motorists by leading an educational action rather than a repressive action
  • Collect traffic statistics (average speed, maximum, number of vehicles etc.) to develop specific actions related to road safety or road improvements
  • Solve a noise problem

The radar speed sign also helps to meet three objectives that are linked together:

  • Enforcing speed limits in areas facing road incivility
  • Linking local regulations and user behavior on the road. Typically, when the radar shows “WARNING SCHOOL” the driver becomes aware of nearby risk and adapts its speed
  • Fight against drivers’ reduced vigilance through visual stimulation (radar range and display visibility, blinking speed, display of a warning message)
How effective is a radar speed sign?

After installation of a radar speed sign, we record speed decreases of around 25% at our customers.

This efficiency is related to the combination of two characteristics that shows its quality: the detection range and visibility.

The psychological impact of the radar speed sign on the behavior of motorists has 2 explanations:

The first is the deterrent effect. Indeed, the radar speed sign generates significant awareness of the drivers and causes slow down. This is usually the case for speeding less than 10MPH :  drivers think they do not drive that fast,  as they are not constantly looking at the speed meter. According to a 2014 study, decline of offenses approaches 50% as motorist pass the radar sign.

For those drivers who are aware of their excessive speed, the fact of showing their speed makes them realize that their speeding is not “trivial”. The fact that everybody (other motorists-pedestrians) can see how fast each vehicle is traveling also contributes to the effectiveness of radar speed sign.

The second explanation is the fear of enforcement. A motorist who sees a radar speed sign understands that the community has put in place specific actions against speeding. He thinks he is therefore more likely to be faced with an enforcement radar in town and slows. This fear is enhanced by the frequent actions led by the Police combining a speed display with enforcement radar guns for instance.

Is a radar speed sign effective in the long term?

Yes, as it is effective immediately after installation, a radar speed sign is still impacting on the long term.

As mentioned above in the question “What is the effectiveness of a radar speed sign”, visual stimulation generated by the radar has a direct psychological impact on the motorist. What makes the difference between one and the other, is the reason behind slow down: deterrent effect or the “fear of the police.” According to a study led between 2012 and 2014, “speed get back to their original level upon removal of the radar speed sign”.

This long-term effectiveness is evidenced by the returns of our clients including those investing again several years after their first installed radar speed sign (over a third of our clients re-order after the acquisition of a Evolis radar speed sign).

To evaluate the effectiveness of a radar speed sign in the long term, we must separate two types of drivers:

Regular users (residents …) are reminded everyday that they are speeding. It has a conscious effect (impact of visual stimulation) and inconscious effect (to be aware of having a dangerous behavior)

Moreover, once they are used to drive gently at a place on a daily commute, it’s easy to maintain this habit with the radar speed sign.

The one-time users of the axis (transit traffic) will be systematically surprised while seeing the radar speed sign and will slow down, even if it is installed long ago.

For what kind of speeding is a radar speed sign efficient ?

A radar speed sign is efficient against all kinds of speeding, as long as the display is adapted to the detected speed. If the speeding does not exceed 10MPH, the speed is is displayed in red together with a text “SLOW DOWN”. For speedings over 10MPH, the speed is displayed in red and flashes, together with a strong alert message (TOO FAST!).

“Small speeders” do not necessarily know they are speeding. The radar speed sign will make them aware and remind them to slow down.

Drivers speeding by more than 10MPH beyond the speed limit are aware about it. In that case, the calming effect is mostly created by the fear of possible enforcement .

What kind of communities do install radar speed signs?

Any kind of community may have to install radar speed signs: Municipalities,Townships, Counties, Councils…

The main buyers are the towns below 5,000 habitants because they are most often facing speeding issues, as they are often crossed by main roads. The radar speed signs shows the best ratio investment  / effect on road safety.

As the concept of “Soothed City” develops, more and more cities reduce their speed limit to 20MPH and are willing to offer their citizens the right means to meet these new limitations by acquiring radar speed signs. Their traffic calming effect is well proven in urban areas.

What are the possible uses of a radar speed sign?

As they can detect any type of vehicles, radar speed signs can be used Parce qu’ils détectent tout type de véhicules, les radars pédagogiques different configurations that will meet the specific needs of communities:

Permanent use : radar speed sign is installed permanently at a chosen location. For instance, a school area or the town entrance.

Semi-permanent use : Moved from time to time (eg every month on a dozen sites) or shared with other communities. Usually installed on existing posts and connected to street light power, or moved with its pole and cocrete block together with the solar panel.

Ultra-mobile use: Punctually installed on a tripod. At school times for example, or on construction sites/roadworks. Most often, this kind of use is combined with particular preventive action with the presence of a municipal agent.


Where are the radar speed signs most commonly installed?

As they are versatile, radar speed signs can be installed in very various locations. They are most commonly installed at:

  • Village/Town entries: the sign reminds the motorists that speed limit is changing, as they leave a road and enter the town
  • Next to schools: allows to secure areas that are dangerous because  attended by numerous children. Some models even allow to display specific messages only at school times (=Caution School)
  • Next to roadworks areas: as for schools, road workers may cross the street anytime. A radar speed sign allows to warn drivers and protect workers.
  • upstream of a crossroad: to avoid potential accidents or to secure a dangeros crossing, radar speed signs are installed upstream and remind motorist to drive carefully.

Whatever the area to secure, installing a radar speed sign requires some precautions:

  • it shall be installed on the street side of the traffic directionand perpendiculary to the road axle.
  • the radar sign shall be perfectly visible and shall not interfere with the readability of road signs in place
  • the bottom of the radar speed sign must be at least 2.20 m from the floor (not to obstruct pedestrians)
How does a radar speed sign work?

A Doppler radar antenna is installed inside the radar speed sign.

It emits magnetic waves that echo on the first moving vehicle. Depending on the frequency of returning wave, the speed is calculated precisely.

This information is then sent to the display. Speed is calculated real-time but displays is refreshed only every second for more visibility.

How reliable is the speed displayed by a radar sign?

The speed displayed by a radar speed sign depends on the Doppler antenna quality and the display refresh capacity. As long as those 2 elements are present in a radar speed sign, displayed speed will be reliable.

Some radar speed signs are equipped with antenna offering an accuracy of +/- 1%. Such models ensure a greater traffic calming effect, as motorists do consider the displayed speed as the right one.

Is a radar speed sign well accepted by motorists and residents?

Undoubtedly yes. Appeared for over a decade now, the radar speed sign has a good reputation and a positive image among local residents.

This image is enhanced as the radar speed sign makes motorists aware of their speed on their own. It makes them drive carefully without going through the enforcement step.

Many studies confirm this observation : for over 90% of respondents, the radar speed sign is informative, preventive and educational. Thus, for a large majority, the installation of a radar speed sign is justified.

How to choose a radar speed sign?

A radar speed sign is efficient if the drivers’ speed decreases. The speed reduction is greater if the confrontation time of the driver with his/her speed is significant.

An efficient radar sign must have a long detection range AND a long distance visibility.

Thus, the detection range and the display quality (number of LEDs, brightness, contrast etc.) are the main characteristics that you need to focus your attention when you want to purchase a radar speed sign.

Models on the market do show huge differences in terms of detection range : some detect up to 150m, some to 300m, and in terms of display: some display speed with 1 line of LEDs where other will use up to 3 lines of LEDs, enhancing long distance visibility and therefore efficiency.

What are the possible power options for a radar speed sign?

A radar speed sign can be powered by:

  • Mains AC
  • Street light network : internal batteries are recharged during street light periods and ensure radar sign operation when street light is off.
  • By solar panel (located on top of the radar speed sign)
  • Autonomous batteries to be recharged manually with an external charger.

Whatever the power mode is, the radar sign will operate the same way towards motorists. The only difference is the mobility, as it is more complicated to move a sign if it is AC connected than a battery operated sign).

How to prevent from race effect?

As the first radar signs appeared over a decade ago, displayed speed was not limited. So they were likely to have the opposite effect than the one desired and caused “racing events” or “record hits”.

Nowadays radar speed signs must be featured with an “anti race” threshold. Depending on countries and local regulations, radar speed sign must not display speed after a certain level beyond the posted speed (usually 10 to 20km/h). In the best case the radar sign shall instead display a warning sign (danger triangle for instance).

Can a radar sign record traffic data?

Yes, a radar speed sign can record traffic data onto its internal memory and they can then be downloaded and analysed.

Using USB, Bluetooth or GPRS, data gathered by the radar sign are transfered onto a PC to be analysed.

Average speed, maximum speed, vehicle counts, V85 are recorded by the radar speed sign in both traffic directions in order to compair drivers behaviours of those who see the sign and those who don’t.

Traffic data softwares usually allow to export data as pdf reports to be shared during councils and published to citizens.

How to install a radar speed sign?

Thanks to technical progress, a radar speed sign can be installed onto various mounts. The power option usually determines the kind of pole where to install the radar sign.

In case of solar power, the radar speed sign is usually mounted onto a dedicated pole with a concrete block. It allows to carry both radar sign and solar panel and to be removed if necessary. Radar sign and solar panel can also be installed onto a pole that is mounted into pre-installed tubes in several locations.

In case of AC power supply (permanent power or street lighting), the radar speed sign is usually installed onto an existing pole. Power is then directly connected from the post.

When the radar speed sign is powered by batteries, it is often installed onto a tripod to be ultra-mobile (this is the case, for radars used by municipal police forces for road safety operations ).

What is the average installing cost of a radar speed sign?

The installation cost (not including purchasing) mostly depends on the power supply option :

  • Solar radar speed sign: concrete block + installation (from $500 to 1,000)
  • AC radar sign: installation of the radar sign onto existing pole. Installing a 30 ma circuit breaker and connection: from $200 to 600

Some radar speed signs are designed to be directly installed by technical teams of the cities. This significantly reduces the cost of installation.

Can I install my radar speed sign on my own?

Yes, a municipality can mount itself a radar speed sign, it’s a position where one can achieve significant savings.

Solar systems require no special skills for models that can be installed by one person. As for the AC signs, they are similar to a connection for Christmas ligthenings.

Moreover, the radar speed sign Evolis requires no particular angle setting. Just install it perpendicular to the axis of the road.


About us

Created in 2005, with now more than 12 years of experience, we are a proud leading manufacturer of radar speed signs and information displays,  distributing in more than 45 countries around the world and growing.


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