Google has announced that it bought Waze, a popular navigation app with crowd-sourced traffic-monitoring powered by its users (see “Social Surveillance Yields Smarter Directions”). It’s a smart move that keeps the startup out of Apple’s clutches and gives Google a chance to grow (and benefit from) one of the few truly useful, important mobile apps to emerge over the past five years.

No purchase price was disclosed, but I’m sure Google paid a nice price for Waze, which has built up a strong community of nearly 50 million people that use its iPhone and Android apps. Waze users report traffic issues and gas prices, and update the service’s maps to give all users a better driving experience. Waze is so good that Apple CEO Tim Cook even name-checked the app in the wake of the disastrous release of Apple Maps last year (see “Rivals Soar After Apple Apology”). As might be expected, Waze had many suitors (Waze CEO Bardin says the company “evaluated many options” before settling on Google).

Naturally, Google plans to make use of Waze’s approach to keeping tabs on traffic conditions to improve the traffic data in Google Maps, and says Google’s search will be added to Waze’z app. The Waze app is to remain remain independent “for now,” says Google, and the company’s product development team will remain in Tel Aviv, Israel, rather than moving to Google HQ in California. In a post on Waze’s blog, CEO Noam Bardin says “nothing practical” will change at Waze, and the company’s employees, management, and founders “are all committed to our vision for many years to come.”