The City of Portland is again punching up parking fines. 

Overtime parking on the street will still get a $39 ticket, but starting Feb. 7, failure to buy and display a meter receipt will get you a $60 fine, up from $45.

The higher fines mean, if you're a parking-meter gambler, the risk has increased. That makes sense to one parking expert.

"When the parking meter was invented, it was described as a combination of a slot machine and an alarm clock," says Donald Shoup, a professor of urban planning at the University of California, Los Angeles.

In Portland, the city doesn't hike these fines alone: The Bureau of Transportation proposes new fines—it's actually called a "bail schedule"—and submits it to the Multnomah County Circuit Court for approval.

Transportation Bureau spokeswoman Cheryl Kuck says the city considers many factors and consults local businesses to make sure parking spaces turn over and people are following the rules, among other key concerns.

"Would a higher amount create a better deterrent?" Kuck says. "Where does Portland stand in terms of the other West Coast cities? Are we getting the behaviors we want on the street?"

Portland's $39 overtime-parking penalty is midrange for the West Coast and comparable cities—San Francisco will ding you $72, for example.

But just how much of a deterrent is a $39 overtime parking fine?

We examined several cities, comparing the size of the overtime parking fine to the cost of one hour of street parking. In other words, if you let your meter expire, what's the magnitude of the fine compared to the extra amount you would have paid to park legally?

Many cities have varying parking rates, something Portland has recently started to try. So we looked at the highest hourly rates in cities compared to overtime parking fines.

Denver's system creates the most risk: The overtime parking fine is 25 times that of the top hourly rate. Portland isn't far behind with 24.4. Seattle—where the top parking rate is $4 but the fine is $44—has one of the lowest ratios, 11-to-1.

Shoup says in some ways, cities are getting the whole parking-fine thing wrong.

His research shows a small number of cars account for a large percentage of the parking tickets issued. These repeat offenders get fined the same amount as someone with only one offense.

"Most of us see ourselves as occasional unintended offenders," Shoup says. "Repeat offenders are nobody's favorite kind of scofflaw. If you increased the fines on repeat offenders, you can have a lower fine for the first offenses. A very small percentage of people out there are truly trying to defraud the city by overstaying at a meter.” 

Olga Kozinskiy and Michael Munkvold contributed to this report.