California became the first U.S. state to launch a medical marijuana program in 1996. On Tuesday, voters will decide whether to legalize the drug for recreational use.

California's Proposition 64 allows adults to grow, consume, and possess small amounts of marijuana.

In California alone, it could open the door to a more than $6 billion industry, according to a recent Arcview Market Research Poll.

Daniel Conway works with Truth Enterprises, a company that invests in legal marijuana businesses primarily on the West Coast.

"Now, what we have is we have a chance to kind of develop a clear set of rules and a real industry around this space," Conway said.

"Medical marijuana in this state is already a $3 (billion) to $5 billion industry," Conway said. "So, we're already talking about a large developing industry here. I think recreational marijuana will be an industry in the tens of billions of dollars."

Investors like Conway face stark criticism from opponents of Prop 64. Doug Villars is the President of the California Association of Highway Patrolman.

"What dollar amount is good for you, for you to sacrifice your life, for you to sacrifice a loved one? Would you be willing to give up somebody who’s important to you just so that comes about?" Villars said. "I'm not. I don't know if you are."

In states that have passed similar laws, Washington for example, the number of fatal crashes involving drivers who recently used marijuana doubled, according to AAA.

Villars says there's really no efficient way to test drivers impaired by marijuana, therefore no way to prosecute.

"It shouldn't be about the money. It shouldn't be about the revenue," Villars said. "If it's about the revenue, we've gone wrong someplace else. If it has to happen, it needs to get the experts together, give us the tools to be able to fight those folks that are abusing the law."

Conway contends the issues surrounding marijuana will persist if Prop 64 doesn't pass. He said it will make the industry more accountable.

Even if the proposition passes, businesses will likely face myriad hurdles navigating the industry and complying with the law.

Kronick is a Sacramento based law firm that recently launched a new practice dedicated to cannabis law. Bruce Scheidt is the managing shareholder.

"Our lawfirm was approached by businesses who were interested in starting either agricultural, delivery, or sales," Scheidt said. "The less time and money they spend in lawsuits, the better it is for everybody.”

Even lawyers are tip-toeing around the issue. Kronick leaders say they're neutral on Prop 64. They'll offer guidance on navigating law but will not represent their clients in court.

"We thought it was the correct line to draw,” Scheidt said. “That to get involved in litigation makes it appears as we're an advocate."

Marijuana is illegal under federal law. The department of justice under president Obama has chosen not to prosecute those in compliance with state law. Regardless of California voters’ decision on the issue, experts say, Proposition 64 may only be the beginning.