The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries.
From iCarTel Team:
iCartel is a free application that will help you reduce the time you spend stuck in traffic. iCartel, based on the MIT CarTel ("Car Telecommunications") research project, builds on a community approach to delivering reliable traffic information and helping users plan around it. iCartel goes far beyond simply displaying red, yellow and green on a street map. Through a combination of current and historic traffic analysis iCartel is able to forecast conditions and suggest routes that keep you out of traffic and get you to your destination on time. *Traffic-aware driving directions that auto-advance as you drive (use the lock button in the lower left to enabled auto-advance) *Accurately predict travel time *Suggests ideal commute time and route to avoid congestion *Collect, log and analyze your trips *Provides the ability to receive background notifications about your favorite routes *Provides support for background logging of position, with intelligent power management (disabled by default) *Built in music player *Routing is enabled for the entire USAs you use the application, the traffic you experience is combined with information from other drivers resulting in traffic information for the roads most important to you, not just the major highways. You also gets an account on icartel.net, a personal commute web portal that shows your recent trips and provides analyses of your drives. Your location information is always held private and never revealed to others. iCartel currently has a user base in Boston that provides a reliable traffic experience. As users in other cities run iCartel, the coverage will drastically increase. Run iCartel, have your co-workers use it and in no time, you will have built a reliable traffic map for your area for all to use!This is a revised version of an application of the same name that was previously available on the app store. It has been released as a new application to support push notifications. Note that continued use of GPS running in the background can dramatically decrease battery life.