NEW YORK — We've all seen reports about head injuries, traffic accidents and even deaths that electric scooter riders have suffered as the popular new mobility option has pushed onto the streets in more than 100 cities worldwide.

Despite the dangers, riders are exposing themselves to liability and are most likely not insured for the damages they may cause.

A rider's personal health insurance — if he or she has it — could help defray the cost of their own medical bills in case of an accident.

But it's another matter entirely when a scooter rider hits and injures a pedestrian, damages someone's property or causes a car accident. The rider may be held responsible, and most insurance policies will not cover those expenses.

"Under the standard insurance policy, there's most likely a pretty significant gap in coverage," said Lucian McMahon, senior research specialist for the Insurance Information Institute. "Even if the odds are low, it doesn't mean that something bad might not happen, and owing people money or compensation for injuries that you caused them can get very, very expensive, perhaps even ruinously so."

The two largest scooter companies in the U.S. — Bird and Lime — generally place the responsibility for accidents on riders by listing in their rental agreements that riders relieve the companies of liability. Customers must agree to those terms to ride.

Bird says riders are fully insured for anything that might happen as a result of a faulty Bird scooter. Lime says its insurance policy offers at least $1 million in liability coverage for each covered claim, but there's no way to know whether a claim is covered until an investigation is done, and each claim is unique.

Despite the scooter companies' liability insurance, experts say responsibility for damages is likely to fall on the riders' shoulders, because of the terms and conditions users agree to when they download the app.

"These are such new modes of transportation that the courts have not weighed in on any of this," said Bryant Greening, attorney and co-founder of LegalRideshare, which represents clients injured in ride-hailing or shared scooter accidents. "Generally speaking, these waivers of liability hold up in court, but we're going to have to see what happens as more and more of these injury cases are brought and are litigated."

Electric scooter riders might think their auto insurance would kick in to cover an electric scooter accident, but automobile insurance generally doesn't cover vehicles with less than four wheels. And homeowner's or renter's insurance may cover an accident that occurs on a traditional bicycle, but it does not cover motorized bike or scooter trips.

"Once you motorized that scooter or that bike, then the equation changes," said Bob Passmore, assistant vice president at the American Property Casualty Insurance Association. "More likely than not, most people's home liability or their renters' liability probably aren't going to provide coverage for that."

So what can scooter riders do to protect themselves? Experts suggest calling your insurance agent to ask how you can get coverage. If you have a homeowner's or renter's insurance policy, you may be able to add an "umbrella policy," which can cover more scenarios and include higher limits for coverage than typical homeowner's or renter's policies.

For example, State Farm offers a personal liability umbrella policy that the company said may cover an electric scooter driver's liability for damages they cause, but all claims are investigated based on their own merits. Allstate offers an umbrella policy to customers that have a qualifying auto or property insurance policy. The umbrella policy doesn't specifically state that it covers electric scooters in promotional materials, but there is a "recreational vehicles" category.

Nationwide's policies do not provide liability coverage for losses arising out of the use of shared electric scooters. The company says it supports shared mobility options and believes the devices should be governed by common-sense regulation that emphasizes safety and protects all road users. "When that is in place, insurance covering the operation of a shared mobility device should be provided directly to the consumer by the device provider," Nationwide said in a statement.

"Read your policy and talk to your insurance agent," Passmore said. "There's certainly some issues that need to be worked out."

Voom, an Israeli company which offers on-demand insurance for drone operators in the U.S., plans to roll out per-ride insurance that covers electric scooters and is targeting riders and providers as potential customers.

"My partner being a scooter owner, and me being a scooter sharing rider, we kind of realized, who is insuring those things?" said Ori Blumenthal, co-founder and CTO of Voom. "If you go to all the scooter sharing companies and you look at the terms and conditions, you actually take responsibility and liability for everything that may happen."

Riders in the U.S. took 38.5 million trips on shared scooters last year, according to the National Association of City Transportation Officials. Within a few days of Chicago's recent electric scooters launch, LegalRideshare got calls from injured riders asking for help.

If a rider causes a car crash, he or she could be badly injured and still be held financially responsible for damages to the car, Greening said. If the rider injures a pedestrian, the rider could be responsible for the pedestrian's medical bills, lost wages and pain and suffering. Many shared electric scooter riders are riding scooters for the first time, increasing the chance of injury, Greening said.

"They don't think to themselves, 'boy if something goes wrong here I might be on the hook for thousands and thousands of dollars,'" Greening said.