Connecticut roads have become increasingly dangerous over the last five years, and this past weekend highlighted a particularly deadly few days in the Nutmeg State.

Nine people have died since Friday and four others suffered serious injuries in seven crashes reported in cities and towns scattered around the state, according to Connecticut State Police and local police agencies. Most of the incidents were single-car crashes involving drivers that left the road and struck either a tree, utility pole or another kind of obstruction, police said.

The fatal crashes were reported in Trumbull, Burlington, Rocky Hill, Stamford, Harwinton, Bristol, Groton and Lisbon.

The crash in Trumbull involved a driver who was seriously injured and a passenger who was pronounced dead at the hospital after the vehicle they were in left the road and hit a rock wall off of Route 8, state police said.

The crash in Bristol involved a motorcyclist who police say failed to negotiate a curve in the road on Route 6.

A crash in Groton took the life of a 14-year-old when police said an SUV with four teens inside left the road and struck a tree. All four occupants became trapped in the vehicle in a wooded area and had to be extricated before they were taken to an area hospital in critical condition. Three of the teens remained hospitalized as of Tuesday.

On Monday, state police said one person was killed when the driver of a pickup truck left Route 12 in Lisbon and struck a pedestrian before hitting a guardrail and a telephone pole. The driver did not report any injuries.

All of the crashes remain under investigation.

The deadly weekend highlights an alarming issue the state has seen since the COVID-19 pandemic. At a news conference last week outside the Connecticut Department of Transportation headquarters in Newington, state officials said Connecticut’s roads in 2019 were safer than they had been in about half a century. That year, 195 deaths were reported.

Since then, the state has seen an influx of traffic-related fatalities which peaked in 2022 with 366 deaths reported on Connecticut roads that year. This was followed by another 316 deaths in 2023.

As of early last week, state officials said Connecticut had already had 245 traffic-related deaths prior to the nine fatalities being reported in four days, including eight in a single weekend. The deadly weekend comes as state police in recent weeks have arrested numerous drivers caught going 100 mph and in some cases more than double the speed limit on state highways. Troopers have also made a number of DUI arrests, including some involving drivers on the wrong side of the highway.

Last Friday, a man was arrested on a DUI when a trooper getting off of Interstate 95 in Milford found that his vehicle was facing the wrong way at a traffic light on the off-ramp. Then on Saturday, a Massachusetts woman was charged with DUI when she was allegedly caught by state police driving the wrong way on Interstate 695 in Killingly just before 5 a.m. State police made another DUI arrest in the early morning hours Sunday after a state trooper pulled a man over for allegedly driving around 100 mph on Interstate 95 in Stamford.

Josh Morgan, a spokesperson for the state DOT, attributed the rise in traffic deaths over the past five years to irresponsible behavior by drivers.

“There’s a crisis on Connecticut’s roadways due to the actions of drivers,” Morgan told The Courant Monday. “They are traveling too fast, being aggressive behind the wheel, and are distracted by their phones.

“People are also being irresponsible by choosing to drive impaired. These selfish and reckless behaviors jeopardize public safety,” Morgan said.

The DOT in recent years has worked to install wrong-way detection systems on the state highways, expand a pilot program involving speed cameras at work sites and has used grant money to upgrade infrastructure to make roads more pedestrian-friendly. Grant funds have also been used to step up traffic enforcement efforts by Connecticut State Police and nearly 40 municipal police departments.

Despite the efforts by state officials to make Connecticut’s roads safer, Morgan said much of the responsibility falls on drivers to follow traffic laws and practice safer driving habits.

“Many of these crashes, injuries, and fatalities can be prevented if drivers followed the rules of the road,” he said. “We need motorists to slow down, pay attention and drive sober.”