Uber announced Wednesday morning it is launching its popular ridesharing services in Beaverton, Gresham, Hillsboro and Tigard, effectively encroaching on Portland, the largest West Coast city to refuse to allow the controversial taxi competitor.

Although Uber says it's simply expanding into new markets, the move could intensify pressure on Portland City Hall to join what the cutting-edge upstart and its users consider an urban-transportation revolution.

Uber's expansion into Beaverton, Tigard and Gresham, all bordering Portland, means that many of the company's drivers will be ferrying passengers through the city.

Residents still can't use Uber's smartphone app for rides that originate in Portland. But nothing in the law prevents Uber's drivers from using their own cars as de facto taxis to pick up passengers in other cities and take them into Portland.

A week after a Portland Bureau of Transportation report showed the city is greatly underserved by taxis when they're needed most, Uber officials said it's getting harder for the city to defend strict ordinances designed to protect the taxi industry from competition.

In fact, Uber spokeswoman Eva Behrend said the mayors of Beaverton, Gresham, Hillsboro and Tigard approached the company about coming to their cities.

"They said they were ready to go," Behrend said. "We see this as an important piece of the puzzle for serving people in this metro area."

It's highly unusual for

, which is based in San Francisco and operates in more than 170 cities worldwide across 43 countries, to enter a metropolitan area via the suburbs. In July,

without as much as a courtesy email telling city officials it was doing business there.

Rather than getting wooed by mayors, Uber regularly faces a death match with taxi companies, politically connected unions and regulators to get its services into cities.

Beaverton Mayor Denny Doyle said he became sold on Uber after using its app to hail local $1.65-per-mile drivers during trips to other cities.

"You can't deny the fact that this service is working in other places," Doyle said. "It's quick. It's convenient. It's cheap."

Among other things, the Beaverton mayor said Uber will provide a much-needed transportation option in fast-growing Washington County cities that are severely underserved by taxi companies.

"Have you ever tried to call a cab at night in Beaverton?" Doyle asked rhetorically. "It's nice to know that people will be able to get a ride when they need it."

In addition to the company's low-cost UberX drivers, Uber offers higher-priced luxury town car and SUV services. With a recent infusion of funding, Uber could see its value top $30 billion, according to a Wall Street Journal report.

Uber has frustrated the taxi industry in every metropolitan area that it has entered, with critics often claiming that the company willfully violates state and local laws. It took a judge's order to allow Uber to roll in Las Vegas two weeks ago.

Uber says thousands of people have attempted to hail a ride with the company's app in Portland. Instead of a car, the app sends them a message that takes a shot at the city's strict taxi regulations.

Meanwhile, Philadelphia authorities have threatened to start arresting Uber drivers after it launched its UberX service even as it told state regulators it had no intention of doing so.

Eugene, Vancouver and Salem have declared that the company's drivers are operating illegally as taxis within its boundaries. Uber disagrees, saying there fundamental differences between it and traditional taxi companies. Behrend said the company is in talks with those cities to resolve the disputes.

Doyle said Beaverton doesn't regulate taxis. With the emergence of the so-called "sharing economy," he said, he sees no point in doing it now. "Yes, there are questions about insurance and other things," Doyle said. "But we're comfortable with treating this like any other new business and watching those things to see what happens."

By contrast, Portland's taxi regulations are among the nation's most restrictive, say Uber and rideshare competitors such as Lyft. Among other things, city code requires a 60-minute advance reservation for non-taxi ride services and sets a strict quota on how many taxi licenses can be handed out during any given year.

So far, the heavily influential Private for-Hire Transportation Board of Review, which includes representatives from the Portland's taxi and town-car companies, have been dead set against relinquishing any of the city's 460 taxi permits to Uber drivers.

Why hasn't Uber gone rogue in Portland? Behrend would only say the company is still evaluating the market and it would prefer to give the city a chance to rework its regulations.

Portland's Commissioner Steve Novick, whose office is leading efforts to examine and possibly rewrite the taxi regulations, said he's not going to rush the process out of fear of looking unhip.

It's not fair to the city's permitted taxi drivers for Uber to compete against a regulated industry without abiding by the same rules, he said. "We want to get it right," he said. "There has to be a way to adopt a less anachronistic system without destroying people's livelihoods."

Uber launching in Portland suburban 4 Gallery: Uber launching in Portland suburban

-- Joseph Rose