Shortly after the state of Washington voted to legalize recreational marijuana late last year, opponents made a very interesting, if somewhat counterintuitive, argument against legalized pot – law enforcement would miss out on the huge revenue stream of seized assets, property, and cash from pot dealers in the state.

Justice Department data shows that seizures in marijuana-related cases nationwide totaled $1 billion from 2002 to 2012, out of the $6.5 billion total seized in all drug busts over that period. This money often goes directly into the budgets of the law enforcement agencies that seized it. One drug task force in Snohomish County, Washington, reduced its budget forecast by 15% after the state voted to legalize marijuana, the Wall Street Journal reported in January. In its most fruitful years, that lone task force had seen more than $1 million in additional funding through seizures from marijuana cases alone, according to the report.

Naturally, this dynamic is something law enforcement either is or should already be preparing for as driverless cars make their way onto the roads. Just as drug cops will lose the income they had seized from pot dealers, state and local governments will need to account for a drastic reduction in fines from traffic violations as autonomous cars stick to the speed limit.

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Google’s driverless cars have now combined to drive more than 700,000 miles on public roads without receiving one citation, The Atlantic reported this week. While this raises a lot of questions about who is responsible to pay for a ticket issued to a speeding autonomous car – current California law would have the person in the driver’s seat responsible, while Google has said the company that designed the car should pay the fine – it also hints at a future where local and state governments will have to operate without a substantial source of revenue.

Approximately 41 million people receive speeding tickets in the U.S. every year, paying out more than $6.2 billion per year, according to statistics from the U.S. Highway Patrol published at StatisticBrain.com. That translates to an estimate $300,000 in speeding ticket revenue per U.S. police officer every year.

State and local governments often lean on this source of income when they hit financial trouble. Last September, Atlanta’s Channel 2 Action News reported that the city’s police union chief claimed in an email to city police officers that Atlanta Mayor Kasim Reed had “designated traffic court/ticket revenue for future pay increases” for police officers. There are countless other examples of police officers increasing their ticket-writing efforts in order to help spike revenue.

And a study released in 2009 examined data over a 13-year period in North Carolina, finding a “statistically significant correlation between a drop in local government revenue one year, and more traffic tickets the next year,” Popular Science reported.

"If a county got one percentage point less money, they gave out around a third of a point more tickets," according to the Popular Science report.

Of course, it’s unclear what exactly the driverless car ecosystem will look like. Tesla CEO Elon Musk, who says his company's autonomous car will be ready for on-street adoption by the masses by 2016, doesn’t believe consumers will adopt fully autonomous cars, but rather those with "a form of 'auto-pilot' in most situations that would allow the vehicle to take over control."

"My opinion is it’s a bridge too far to go to fully autonomous cars," Musk told the Financial Times last September. "It’s incredibly hard to get the last few percent."

Musk makes a good point. A car that can drive you home when you’re tired or have had too much to drink seems like a great idea, but consumers may not be crazy about being restricted to speed limit-abiding robots when they’re running late for a meeting or about to miss a flight. This could also explain why Google has reportedly had difficulty finding a manufacturing partner for its fully autonomous car, as the Financial Times pointed out in its article about Musk.

The question, however, is how much of an impact any autonomous driving ability has on the reliable revenue source that traffic violation fines have been in the public sector. If and when drivers decide to switch off their autonomous drivers and double the speed limit on a joy ride, will police be able to pay enough officers to stop them?