Uber, Lyft, and Sidecar get tentative green light in Calif.

After swinging a series of punches, it's looking like the state of California may be calling a truce with ride-sharing app companies.

The California Public Utilities Commission published a proposal on Tuesday that said it would allow companies like Uber, Sidecar, and Lyft to operate in the state if they adhered to certain guidelines. These guidelines require drivers to be licensed by the CPUC, go through criminal background checks, attend driver-training programs, carry $1 million per-incident insurance coverage, and have a zero-tolerance policy on drugs and alcohol.

"The Commission is aware that TNCs [Transportation Network Company] are a nascent industry," the proposal reads. "Innovation does not, however, alter the Commission's obligation to protect public safety, especially where, as here, the core service being provided -- passenger transportation on public roadways -- has potential safety impacts for third parties and property."

While the rules may seem stringent, many ride-sharing app companies are calling the proposal a success.

Sidecar CEO Sunil Paul wrote in a blog post, "We couldn't be more pleased with this outcome and applaud the CPUC for moving in favor of transportation innovation and consumer choice." And, Lyft co-founders John Zimmer and Logan Green wrote, "With the guidelines outlined in the proposed decision, the CPUC has set a new standard for safety in transportation while supporting innovation that makes cities safer, more affordable and better connected."

Uber also wrote a blog post that said CPUC's proposed decision "reaffirms that Uber's core business model of working with professionally licensed and regulated transportation providers can continue without change, while paving the way for a long-term regulatory framework for peer-to-peer ride-sharing services."

Companies like Uber, Lyft, and Sidecar have been working to bring ride-sharing apps to metropolitan areas across the U.S. over the past year or so. However, they have come up against many regulatory hurdles. After a long back-and-forth with New York's Taxi and Limousine Commission, the city finally started allowing ride-sharing apps in a pilot program in April. And, other cites, like Chicago, Washington, D.C., Denver, and Miami have also hashed it out with these companies in the past.

In California, officials in both San Francisco and Los Angeles have butted heads with the ride-sharing apps. Last November, San Francisco cab drivers filed a class-action suit against Uber claiming unfair business practices; and in June, the Los Angeles Department of Transportation sent cease-and-desist letters to Uber, Lyft, and Sidecar claiming they were operating unlicensed commercial transportation services.

After all of these battles, the ride-sharing apps are likely pleased at the prospect of now cooperating with California regulators. The CPUC's proposal still has to be adopted by the Commission, but this could happen as soon as September 5.