Google Maps enthusiasts are in for a treat.

From Wednesday noon, commuters in India get turn-by-turn, voice-guided directions, using the Google Maps Navigation. In addition, if you’re living in Bangalore, Mumbai, New Delhi, Chennai, Pune and Hyderabad, you’ll find that a new advanced feature just got activated on your maps menu — live traffic updates.

Both services provide real-time information free on smartphones running on Android 2.2 (or later). Traffic updates are also accessible through desktop browsers. However, the data relies only on crowd-sourced information from Android phones to provide live updates on the average speed of vehicles on major roads.

Tech forums had been abuzz with news on a likely announcement on maps when Google Inc made the formal announcement here. The service, which is available in 40 languages in 74 countries, is now offered only in English. However, the announcement of upcoming directions (in the navigation service) is in a “friendly, familiar Indian accent,” according to Darren Baker, product manager for Google Maps. India is “a dynamic and fast-growing market for online map services.”

The Internet-connected GPS navigation service draws on Google’s search and voice search capabilities. Besides announcing simple ‘right and left’ directions, the service offers layers that give one en route information on popular landmarks, restaurants, ATMs or petrol bunks. Another advantage is that since the data is accessed through Google’s mapping services, there is no need for manual updates.

Google Maps users in the select cities, through desktop browsers, can view real-time traffic updates for major roads by enabling the ‘traffic’ layer. Another feature allows one to see ‘typical’ traffic conditions at a given time, on a given day, by referencing historic data. Traffic information is displayed in a simple readable colour scheme, indicating various speeds of the vehicles .

But here’s the catch: this live feed, used by Google’s algorithms to predict traffic situations, is based on information gathered from Android phones that may be travelling along that particular route. Given the low smartphone penetration in India and that getting data from these phones will also require Android users to give permission to share their GPS data, this information may not be as ‘reliable’ or ‘accurate’ as Google proposes.