I get on the M34 bus last Wednesday, insert my MetroCard, and sit down to read the newspaper. Two stops later at Park and 34th Street, a uniformed MTA guy jumps on through the rear door. "Where's your receipt?" he demands.

"Excuse me?" I ask. "I paid my fare. You can ask the driver."

"Step off the bus."

But my stop isn't --

"Step off now."

Why?

"Fare evasion."

Special Insp. Padro demands ID. I reluctantly hand over my driver's license. He then requests my Social Security number. Seriously? I refuse.

"Off the bus," he repeats, and I comply. Didn't I know to get a receipt from the machine on the street for Select Bus Service routes?

No, I usually ride the subway, and there aren't any SBS buses in my neighborhood, I tell him. If I'm supposed to present a receipt, why didn't the bus driver ask for one?

But Padro is already scribbling a ticket.

Last year, such fare evasion tickets accounted for more than three-quarters of dollars the MTA raked in from all rules violations. When I get off, I step past a bewildered, non-English-speaking woman who was also nabbed.

Supervisor Arthur Bianchini steps over to me. Pleasant enough man. He requests and inspects my MetroCard, then asks where and when I got on. If I want to contest the ticket, he tells me, I can go to court, and my MetroCard will confirm if I'm telling the truth.

Padro hands me the ticket. $100!

Smoking on the subway carries a $50 fine. Not having a bus receipt is double that?

And where is court? Somewhere in Brooklyn. Between the subway ride and the hearing, we're talking about a half-day wasted. Most people can't afford to take off from work for that. You know some just swallow hard and pay the ticket, even if they've paid the fare.

As I walk off, Bianchini calls out "just doing my job."

A few minutes later, it hits me. Why don't the inspectors carry a MetroCard scanner? They could have swiped my card and instantly known if I was telling the truth.

But then they couldn't have written a $100 ticket.

I'm going to court today. Should be a load of laughs.