The US Internet search giant did not reveal the price of the acquisition, but Israeli media over the weekend estimated the deal was worth more than $1 billion.
"To help you outsmart traffic, today we're excited to announce we've closed the acquisition of Waze," said Brian McClendon, vice president of Google's Geo products, which includes Google Maps, Earth and Street View.
"This fast-growing community of traffic-obsessed drivers is working together to find the best routes from home to work, every day."
McClendon said that Waze's development team would remain in Israel and operate separately "for now."
"We're excited about the prospect of enhancing Google Maps with some of the traffic update features provided by Waze and enhancing Waze with Google's search capabilities."
The big-ticket takeover comes as Google duels with Apple (NasdaqGS: AAPL - news) and other rivals to be at the heart of mobile Internet lifestyles, particularly when it comes to providing advertising or services relevant to where people are at any moment.
Waze taps into the collective knowledge of road warriors in order to make life more pleasant for drivers while creating reliable street maps.
A free Waze service that proved its worth in Israel made its US debut about four years ago, inviting motorists to use smart phones to keep one another in the know about speed traps, short cuts, hazards, accidents and more.
"It seems like a silly thing, but it is addictive," Waze chief executive Noam Bardin told AFP at the time of the US debut.
"There is this feeling that you are not alone... Some people just like knowing someone else is out there."
Satellite tracking technology commonly built into smart phones lets Waze automatically measure traffic flow while simultaneously verifying or modifying public street information in its database.
Motorists "teach" Waze computers where roads are and how best to maneuver about simply by driving.
Drivers can upload comments, along with pictures, from along their routes to alert fellow "wazers" to anything from accidents or detours to a favorite place to grab a cup of coffee. Waze also provides users with turn-by-turn directions.
While Waze acts as a handy, free navigation tool for drivers, it is at its core a "wiki" style approach to map making: Waze users are essentially feeding updated street information to the service every time they drive.
The low-cost, crowd-sourcing approach generates up-to-date street maps that compete with offerings from leading mapping data firms that sell data to companies running Internet mapping or in-car navigation services.
The project was named "Freemap" when it was launched in Israel in 2006 to create a "live" map of that country.
"Google is committed to help us achieve our common goal and provide us with the independence and resources we need to succeed," Bardin said in a blog post.
"We evaluated many options and believe Google is the best partner for Waze, our map editors, area managers, champs and nearly 50 million Wazers globally."
Keeping Waze out of the hands of rivals was likely among the reasons Google bought the startup, according to independent technology analyst Jeff Kagan.
Google is tops in online maps and navigation, but Apple has been refining its own mapping software for iPhones and iPads and Facebook is keen to follow members increasingly accessing the social network from mobile devices.
"Google may have a leadership position in the navigation space today, but that means they also have to work twice as hard to keep that position," Kagan said.
"Waze will not transform Google navigation on its own, but it will add another flavor and choice and innovation always keep customers coming back for more."