Metra riders running late can hop on a train and pay the conductor in cash — for now.

The rail service is looking at whether — and how — to eliminate cash fares paid on board (cash still would be accepted at ticket windows).

The primary reason for considering the policy change is to speed up the ticketing process, said Michael Gillis, a Metra spokesman. Cash fares paid on board include a $5 surcharge.

The policy change, floated by Metra CEO Jim Derwinski at the agency’s December board meeting, would allow conductors to stop carrying cash. Though robberies of and safety complaints from conductors are rare, Gillis said, cash handling on trains is still a security issue.

There’s no timeline for switching, Gillis said.

Metra ticket machines in train stations are credit-card-only, and there are only a few at Union Station and the Ogilvie Transportation Center. So if the switch is made, the agency may add machines that take cash. Another alternative is the Ventra app. Besides being used for the CTA, it also allows riders to buy and display Metra tickets on their smartphones.

“They should continue both [cash and non-cash ticketing],” said Ernesto Muro, 24, a commuter from Glendale Heights. “The Ventra app helps a lot — it’s very effective, very helpful — but sometimes people might not have much experience with technology, so maybe keep the cash going.”

That’s the problem Metra rider Ken Sahs, 60, fears he might face.

“I’m not real big on using technology for that kind of stuff,” said Sahs, who commutes from Chicago to Arlington Heights for work 3 to 4 times a week. “I see a lot of people pay with their phone with the app. I don’t like that. I’m 60 years old, so it’s a little out of my time.”

He added that if Metra eliminated on-board cash ticketing, he “probably wouldn’t be taking the train.”

What to do if a passenger boards a train without a ticket has not yet been discussed, Gillis said; however, he added, similar transit systems typically require proof of payment before boarding, or assess a fine on passengers caught with no ticket.