Traffic fatalities are on the rise this year on Las Vegas streets, a problem that in some respects can only be solved by area drivers.

Clark County Sheriff Joe Lombardo, in diagnosing the increase in fatalities, listed such factors as excessive speed, intoxication and cellphone use, all of which can really only be addressed by motorists accepting the responsibility to drive more safely and be more considerate of others on the road.

But elected leaders also have a responsibility to address traffic safety, and a new study suggests a way that they can play a major role in reducing the threat level.

The study shows that traffic fatalities tend to be lower in metro areas with heavily used public transportation systems compared to metros where fewer people use such systems. Its conclusion: Enhancing and expanding public transportation systems significantly increases traffic safety.

Upfront, it should be noted that the study was produced by a partnership that includes the American Public Transportation Association, an advocacy organization. So yes, the report may at first glance seem self-serving.

But the study is airtight, partly because of its simplicity. It uses federal data comparing the number of public transportation trips per capita with the traffic fatality rate in the 108 largest U.S. cities.

Using those metrics, researchers found that the 11 metro areas with more than 40 transit trips per capita had a fatality rate far below average — 5.7 fatalities per 100,000 residents, compared to the average of 9.9 percent. Boston, Chicago, Philadelphia and Washington, D.C., are among the 11 metro areas with the heaviest use of public transit. The numbers for Las Vegas are 9.3 fatalities per 100,000 residents and 36.1 transit trips per capita, which are encouraging. The study showed that safety improved sharply once communities hit the threshold of 40 transit trips, and we’re close to hitting that level.

The study’s conclusion is perfectly intuitive. Not only are buses, light-rail systems and other forms of public transportation safer than automobiles, but they reduce the number of cars on the road by providing motorists with an alternative to using private vehicles.

In addition, public transportation offers a responsible option for people who may not be comfortable getting behind the wheel, like inexperienced drivers, seniors or those who have had a few drinks or struggle to resist texting while driving. The result is safer roads.

Granted, many other factors affect vehicular death rates, including road design, traffic enforcement and even weather.

But there’s no question that public transportation is a key piece of the puzzle in traffic safety.

“One of the most powerful traffic safety tools a city can employ to eliminate deaths and injuries due to road traffic crashes is its public transportation system,” Paul Skoutelas, president and CEO of APTA,said in a recent conference call. “It takes just a modest increase in public transit use to result in a dramatic decrease in traffic fatalities.”

Statements like that should cause local leaders’ ears to perk up.

Although this year’s increase in fatal accidents is modest — three above the year-to-date level in 2017, as of Tuesday — the trend promises to go nowhere but up as the valley's population grows and more vehicles pour onto the streets. From there, it’s a simple but deadly equation. More drivers mean more people driving badly, recklessly or inattentively, which equals more accidents and deaths.

For this reason and others, it’s imperative for local leaders to push hard for light-rail development, starting by the proposed light-rail system that emerged this summer from the Regional Transportation Commission. The $750 million system, which would run from Maryland Parkway near McCarran International Airport to downtown and the UMC complex, should be treated as the starting point for something far bigger — starting with a line on the Strip.

Besides saving lives, light rail would allow Las Vegas to maintain its economic vitality by giving tourists and conventiongoers a convenient and quick way to get around, thereby enhancing the visitor experience that’s become our key selling point as a travel destination.

For local residents, the system would provide easier access to work, their doctor’s office, shopping, entertainment and more, all without facing traffic congestion and finding parking. Another major benefit to the community: Light rail has sparked billions of dollars in business development in communities where systems have been built — $8.2 billion in Phoenix, according to the latest figures

But safety is one of several key reasons to bring light rail to Las Vegas.

To the credit of local law enforcement authorities, they’ve addressed the increase in fatalities this year by making public pleas for drivers to slow down, obey the law and pay attention.

But that approach can only take us so far.

As the message sinks in, light rail stands as a proven solution to our growing problem with traffic safety. Community leaders need to move it forward full-speed.