Do Speed Cameras Actually Work? A look at the impact on roadway safety

Despite a steady decline in overall speed-related fatalities, speeding remains a prevalent traffic safety issue in the USA. Roughly 25 percent of all fatal traffic collisions now involve at least one speeding driver. Analysts at Injury Facts estimate at least 25 Americans die every day in a speed-related accident. 

To help address this speeding issue, many states have begun experimenting with motion-detecting radars on accident-prone roads. To be precise, 16 states (plus the District of Columbia) have installed “speed cameras” to monitor drivers who travel over the speed limit. These cameras promise to take the burden of speed enforcement off police units—but do they work as promised? Do motorists modify their speeding if they know speed cameras are in use? Or are these cameras a sneaky way for the state to collect more money? 

Since speed cameras are such a novel innovation, there’s still a great deal we don’t know about their long-term effects. However, there is enough preliminary data to suggest speed cameras could positively impact road safety. Let’s take a closer look at what the most up-to-date research on speed cameras has to say.  

How Do Speed Cameras Work?

Before analyzing the effectiveness of speed cameras, let’s first ensure you know what these devices are. As you could tell from the name, speed cameras are radars designed to track how fast vehicles are moving on select roads. 

If the scanner detects you’re moving at least 10 mph over the posted speed limit, it will take a photo of your vehicle. Government employees will then use the license plate in your picture to send you a speeding ticket. 

Do Speed Cameras Make Roads Safer? – A Few Initial Findings 

To understand whether speed cameras work or not, we have to take a trip to Maryland. Interestingly, Maryland is one of the nation’s earliest adopters of speed cameras, which means most of the data we have on this technology comes from the Old Line State.  

Before Maryland implemented speed cameras in work zones, roughly seven out of every 100 motorists would speed through hazardous areas. Impressively, between 2010 and 2017, these speeding rates dropped by at least 90 percent on roads with cameras. Maryland’s Department of Legislative Services also says speed-related fatalities in work zones with cameras went down by almost seven people year-on-year.  

Analysts at AAA Mid-Atlantic also suggest speed cameras have been “paying off” for residents. No, we don’t mean government officials have been earning more since these cameras have been installed. Just the opposite: revenue from speed cameras went down by at least 44 percent in recent years. This suggests more drivers in Maryland are taking their speed seriously.   

Outside of Maryland, the IIHS has also conducted a few studies on speed cameras in Arizona and Washington, DC. According to these eight-month trials, cameras reduced speeding by 88 percent on Arizona highways and 82 percent in the nation’s capital. 

But perhaps the most comprehensive study on speed camera safety didn’t occur in the USA. Indeed, Australian researchers at the University of Queensland recently looked for correlations between 35 studies on speed cameras. According to this thorough meta-analysis, vehicles on roads with cameras reduced their speed by between 1 – 15 percent compared with non-camera roads. Researchers also pointed out average crashes went down 8 – 49 percent on camera roads, with fatal crashes dipping 11 – 44 percent. 

Sneaky or Easy-To-See? — Which Cameras Work Better? 

One issue road safety crews have to consider before installing speed cameras is whether they will be noticeable or discreet. Although there are pros and cons associated with both of these strategies, most data supports prominent cameras and clear signage.  

The more apparent cameras are, the more likely motorists seem to slow down in the targeted area. Data from Montgomery County, Maryland, found that 70 percent of motorists reduced their speed on roads with both signs and cameras. By contrast, 39 percent of drivers on roads with only signs reduced their speed. 

Not only do obvious cameras deter speeding drivers, but they also seem to have a positive effect on the community. It’s common for motorists to express negative feelings towards new cameras, especially if they get the impression they are being used to generate revenue rather than promote public safety. Since covert cameras are hidden, motorists might feel like the government isn’t playing fair.  

In the Montgomery County study mentioned above, researchers asked community members for opinions on conspicuous speed cameras. Survey results suggested that over 60 percent of residents were in favor of these devices. By contrast, the CDC notes it’s challenging to gain acceptance from the community with hidden cameras.     

There are, however, advantages to adding a few covert cameras to a city’s design. For instance, the CDC points out hidden cameras could help gauge speeding on secondary roads. Covert cameras could also give residents the sense that speed enforcement is all-pervasive, encouraging them to change their driving habits. 

Do Speed Cameras Have A Positive “Spillover” Effect? 

Most often, speed cameras are only placed on major roads that have issues with speed crashes. While this appears to be an effective strategy, there’s some debate over whether these cameras have any positive safety effects in surrounding areas. 

Do motorists maintain the posted speed limit even after they leave an area with speed cameras? Will motorists go out of their way to avoid speed cameras, thus increasing accidents on secondary roads? 

Unfortunately, we don’t have conclusive evidence on these crucial safety issues. However, the previously mentioned Montgomery County study suggested speeding fatalities and injuries dropped by over 25 percent on streets surrounding speed cameras. The CDC also noted these findings in a recent report. 

While this data is encouraging, we still need more info to fully understand how speed cameras affect driving in surrounding areas. Until we better understand this issue, the CDC recommends regular patrolling as an effective deterrent for speeding on secondary roads. 

Will Speed Cameras Be A Fixture on Future US Roads?  

As more studies suggest that speed cameras could reduce the crashes, it’s more likely you’ll find a few of these devices in your hometown. In fact, one of the nation’s biggest cities—Philadelphia—is undergoing a major speed camera initiative along the notoriously accident-prone Roosevelt Boulevard. 

There will soon be 32 cameras in Northeastern Philly running a 12 mile stretch of roadway. Citing studies from the CDC, Philadelphia’s Mayor Jim Kenney believes this new technology could reduce speeding incidents by 20 – 25 percent.   

As more cities like Philadelphia install speed cameras, it’s unlikely this trend will diminish anytime soon. Not only do these speed cameras seem to prevent crashes, but they could also improve the efficiency of police units across the USA.  

For a full list of where speed cameras are currently installed, be sure to read through this list put together by the CDC.