The driver of a pickup truck was charged with second-degree murder and operating while intoxicated after striking a group of bicyclists near Kalamazoo, Mich., authorities said. The National Transportation Safety Board recently published a preliminary report on the accident. (Jillian Kitchener/Reuters)

The National Transportation Safety Board, the federal agency that’s often the last word on air, rail and other crashes, has issued a preliminary report on the Michigan bicycle crash that killed five bicyclists and injured four others earlier this summer.

The nine bicyclists, who were part of a private club known as the Chain Gang, were on a 28.5-mile trip when a pickup truck hit them, the NTSB says. The pickup, which was traveling in the same direction as the bikers, left the roadway for unknown reasons and drove onto the paved, four-foot-wide shoulder where the bikers were pedaling, striking the entire group from the rear.

The pickup’s driver, Charles Pickett Jr., 50, who allegedly popped muscle relaxants and pain pills before getting behind the wheel, is awaiting trial on charges that include second-degree murder and operating a vehicle while intoxicated, local media reports say.

The preliminary NTSB report does not provide much more detail than many media accounts of the June 7 accident near Kalamazoo. But the NTSB’s interest in a bicycle accident is unusual. The agency decided that the crash was worth investigating not only because of its severity but because of the growing popularity of bicycling as an alternative to vehicles.

“We last looked at cycling in the early 1970s,” NTSB spokesman Eric Weiss said in an email Tuesday. “We’re looking at the Kalamazoo crash as part of an effort to examine the future roadway, where cars and trucks increasingly share the road with cyclists and pedestrians.”

The agency is also interested in understanding and combating the impact of substance abuse and impaired driving on accidents, according to the preliminary report, which was posted online Aug. 3.

The Streetsblog Network, in a post this week, welcomed the NTSB’s investigation but suggested that the independent federal agency should go beyond the Kalamazoo crash to a systematic study of the causes of fatal bicycle crashes.

More than 900 bicyclists were killed, and approximately 494,000 were taken to emergency rooms for injuries in 2013, according to the Centers for Disease Control and Prevention. MLive.com, in an analysis of Michigan State Police accident data, found that the state’s bicycle fatalities had risen 57 percent compared with the previous year, even before the Kalamazoo fatalities. The National Highway Transportation Administration (NHTSA) says motor vehicle crashes significantly underestimate the number of injured pedestrians and bicyclists.

In the crash near Kalamazoo, there were no rumble strips or pavement markings designating a bike lane, the NTSB says — a finding that fits with MLive’s report that 93 percent of crashes in 2015 that they examined occurred on streets without a dedicated bike lane.

There’s another interesting question about this case, too. Prior to the crash, police received multiple notifications that Pickett’s truck was traveling in an erratic manner. The first call came in 22 minutes before Pickett hit the bicyclists.

One man told police that the pickup went off the road and through the witness’s yard in such helter-skelter fashion that he thought the truck was under pursuit. Another witness said a pickup was tailgating him so closely that the witness could see leaves in the grill, as if the driver behind him had hit something. The witness also said the driver was weaving back and forth over the center line as if he were drunk.

Many of us have been in similar situations, when you see someone driving like a maniac and wonder whether the police should be alerted. It often seems as if no matter how quickly you make the call or how quickly police respond, there’s not a whole lot that can be done — and that the only benefit might be helping to document a driver’s recklessness after the fact.

It will be interesting to see whether the NTSB can shed any light on how law enforcement handled those calls, and whether there might be things that police could do to track such down such vehicles more quickly or that motorists could do to help them.

Read more from Tripping: