Nine members of Congress sent a letter to the CEOs of Uber, Lyft, Juno, Curb, and Via on Monday requesting details about their protocols related to sexual assault and harassment reports, training drivers, and more.

The letter, first seen by CNN, came following a recent CNN investigation that found at least 103 Uber drivers in the United States have been accused of sexually assaulting or abusing their passengers in the past four years.

"The questions we're asking are, in many senses, common sense questions that we'd hope the ridesharing companies would already be doing, like maintaining records of driver who've been accused of sexual violence," said Democratic Caucus Chairman Joe Crowley of New York, who drafted the letter along with Congresswoman Lois Frankel of Florida. "[CNN's] article really begged these questions in many respects."

The letter asks if the companies maintain records on drivers who've been accused of sexual violence and do they make that information public. It also wants to know if the companies have protocols in place to alert other ridesharing companies if drivers on their platform are reported for harassment or discrimination. Drivers often work for multiple companies.

"I have a [17-year-old] daughter, and I want her to know that when she's going to and from a place, she should be safe and not assaulted or sexually attacked," Crowley said in a phone interview. "Regardless of what condition the individual was in during a ride, they have every right to expect that they're treated with respect, dignity and honor."

Many of the women who say they were raped or attacked by the 103 accused drivers uncovered as a part of CNN's investigation had been drinking, or were inebriated, at the time of the incidents.

CNN's analysis came from an in-depth review of police reports, federal court records and county court databases for 20 major US cities. At least 31 of the Uber drivers have been convicted for crimes ranging from forcible touching and false imprisonment to rape, and dozens of criminal and civil cases are pending, CNN found.

Lyft, Uber's biggest US competitor, had 18 cases of its drivers accused of sexual assault or abuse in the past four years, according to a similar CNN review using the same methodology found. Drivers were either arrested, are wanted by police, or have been named in civil suits related to the incidents. Four Lyft drivers have been convicted.

CNN found two instances in which drivers pleaded guilty to sexual assaults while working for both Uber and Lyft.

Five Uber drivers across various states told CNN as part of the investigation that they were not provided any kind of sexual harassment or assault training. Drivers agree to the company's community guidelines when they sign up to work for the service. Uber said it updated its standards in December 2016 to specify no sexual contact is permitted when using its platform.

The letter puts new pressure on the companies to be transparent about their internal protocols and safety measures pertaining to sexual violence.

"We do expect [the companies] to respond in a very forthright way," said Crowley. "It may very well -- depending on the answers they give -- require additional investigating, additional reporting, and at some point, a possible hearing."

The inquiries from the lawmakers are similar to questions CNN pressed Uber and Lyft on as part of the investigation.

Neither company disclosed data on the number of reports received from riders, but both promised last week to publish data in the future.

"We want to bring these numbers out in the open. We want people to acknowledge the enormity of the issue, and we want us to begin to think of constructive ways to prevent and end sexual assault," said Tony West, Uber's chief legal officer, told CNN last week.

The companies also agreed to stop forcing survivors into arbitration and will no longer require confidentiality as a part of settlements. However, survivors won't be able to pursue class action lawsuits.

"Eliminating forced arbitration and making confidentiality an option for survivors are good steps forward. There's more work to be done to ensure safety and fairness," said Frankel in a statement to CNN.

But Crowley also praised some of the recent updates Uber has made to commit to safety. In April, the company said it was tightening its background check processes and rerunning background checks annually.

Although the letter doesn't give a deadline for the CEOs to respond, Crowley said, "We expect a response within a reasonable amount of time."

-- CNN's Nelli Black, Curt Devine, Drew Griffin, Majlie de Puy Kamp, Collette Richards and Whitney Clegg contributed reporting.