Welcome to iCartel

[ Intro | Getting Started | Main Display | Traffic | Routing | Settings | Website | Privacy | About | Contact | FAQ ]

Introduction
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iCartel is a free application that will help you reduce the time you spend stuck in road traffic by delivering traffic reports and calculating good routes for you. It runs on the 3G or 3GS iPhones. The underlying technology includes a "crowdsourced" approach to collect data from phones (and other sources), using that to predict traffic delays at times in the future, and to use these delay predictions to propose traffic-aware routes that will take you on roads that are likely to experience the lowest congestion and delay. By using the application as you drive, your phone provides traffic delay data to our servers and (after significant processing), provides consolidated traffic information to other drivers. Your location information is held private and not revealed to other users. In addition, a "drive log" on your personal commute portal (at icartel.net) shows the recent trips you have made and various analyses of your drives.

Getting Started
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When you start iCartel for the first time, you will be presented with a registration dialog (see Figure 1). You will be asked to specify a username and password, which will be associated with your phone on the iCartel website. You can opt not to register immediately (by clicking "Ask Later"), but you will not be able to see your data on icartel.net until you register. Registration requires a working network connection to the server.

CarTel registration dialog
Figure 1: The registration dialog.

The Main Screen
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Figure 2 shows the main display of iCartel, which includes:
  • The GPS status light: this icon spins when the system is recording your location, and changes color to indicate the quality of the estimate of your position. Red indicates very uncertain, yellow somewhat uncertain, and green relatively certain. If the "position filtering" option is turned on in preferences, your location will only be sent to the iCartel server when the status light is green.
  • The "show details" arrow: press this arrow to see additional details about your drive (since you last hit the "reset" button), including total drive time, as well as your speed and pace. See Figure 3.
  • The reset button: press this button to clear the display of your GPS trace and reset the statistics about your current drive.
  • The main switch: press this button to stop recording information about your position and to stop the drive timer.
  • Your current position: Shown as a faintly pulsing blue sphere.
  • Route finder: Click this button to find the fastest route from your current location to a destination.
  • Preferences: Use this button to configure the iCartel preferences.

Cartel main display
Figure 2: The main display of iCartel.
Cartel detail disclosure
Figure 3: The information panel is shown when the detail disclosure button is clicked.

Viewing Traffic
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Traffic is shown as a series of red, yellow, or green line on top of roads, as shown in Figure 2 above. Red indicates that traffic is not free flowing on that road (speed less than a third of the speed limit), yellow indicates that it is slightly delayed, and green indicates that there are no delays. Traffic data is automatically refreshed every few minutes. Traffic data will not be available if there is no network connection. If a road is not colored, it means our system has no current data about that road.

Finding Routes
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To find a route, use the "route finder" (the magnifying lens) button in the lower left of the main interface. You will be presented with the search dialog shown in Figure 4. You can type a destination into the search bar at the top, or select one of the previously used destinations from the scrolling list at the bottom. The system currently only is able to route from your current location to a destination.

Cartel routing interface
Figure 4: The routing interface.

When you select a destination, the system contacts our routing server to find a route. This may take up to 30 seconds to return an answer, though for paths to nearby destinations, the system should return much more quickly. For far away destinations (>20 miles), the server may refuse to compute a route for you; we are currently working on optimizing our traffic-aware routing algorithms to be able to address this issue.

You can cancel the route finding using the white "x" icon in the lower left of the interface. While routing is happening, you may go back to the map interface using the "Map" button in the upper left; the system will automatically display the route once routing completes.

When the route is available, you will be taken to back to the map interface, and the route will be overlaid in pink on the map (see Figure 5). The route controller will be shown in the bottom right button, along with the expected travel time for the route. When you click the "Follow" button, iCartel will change into follow mode (Figure 6) which you can use see the details of each turn along the route by clicking on the "Next" and "Prev" buttons. You can exit Follow Mode by clicking the "Stop" button.

You can also use the reroute button () to recompute the route from your current location to the last selected destination without returning to the routing screen.

Cartel route display
Figure 5: A route displayed on the main interface.
Following a route
Figure 6: Following a route using the "follow" button.

Settings
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The settings panel (accessed from the settings button on the main view and shown in Figure 6) can be used to configure some basic properties of the system. The options are as follows:

  • Filter data: If this option is on, the phone will only display and transmit your location when the location estimate is good (the GPS status shows green). This will lead to more accurate estimates of distance traveled and approximations of your route, but getting a good location fix can take several minutes.
  • Keep awake: When this option is on, iCartel will instruct the iPhone to leave this display on and not sleep. This is useful if you are using the application while driving. Leaving the screen on continuously, however, uses substantial battery life. In our testing, we have found that the iCartel application gets about three hours of battery life on a full charge when the display is on at maximum brightness and GPS data is being logged over the 3G radio.
  • Show traffic: Configures whether or not traffic is being displayed on the map.
  • Streets/Satellite/Hybrid: Controls the type of Google map that is displayed.
  • Drive/Bike/Walk: Specifies the type of activity you are performing. You can search on the iCartel website for drives of a specific type, and we use the activity to avoid integrating walking/biking data into our traffic predictions. Note that recommended routes are currently only for driving, and are not affected by this setting.

Preferences
Figure 7: The settings interface.

Logging onto the iCartel Website
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To log on to the iCartel commute portal and browse your driving data, visit http://icartel.net and log on with the user name and password you set up when you configured the application.

What we collect and our privacy policy
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When the iPhone application "main switch" is in the "on" position, the application will send your position, as well as the ID of your phone, to our servers. This position is stored in a database and used for traffic prediction, as discussed below.

Your phone ID is a unique number associated with your phone. Only Apple (and possibly AT&T) can convert this number to personally identifiable information about you. You are not required to provide your real name, address, or email to use the iCartel application or website.

Your position data will be used in three ways:

  1. Your data may be used by the iCartel team (mainly researchers at MIT) for purposes of traffic modeling and prediction. Members of the team do not receive identifying information about you or your phone when working with this data.
  2. Your data will be matched to the underlying road network and combined with data from other drivers to compute traffic delays which are sent to other users of iCartel and displayed on our website. Your phone ID and any information specified in your account on http://icartel.net. is stripped from the data during this combination process.
  3. Your data will be displayed to you when you log into the iCartel website at http://icartel.net. Using the iCartel website, you may see the raw information we have collected about you and delete your drives from our website.

About iCartel
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iCartel is a result of the CarTel project at MIT.

Contacting Us

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Comments or questions? Please email us at icartel at the domain mail.icartel.net.

For up to date answers and questions, see the iCartel FAQ.

Credits

iCartel was developed by Sam Madden, Paresh Malalur, and Hari Balakrishnan.

The icartel.net trip-logging and analysis web site was developed by Sam Madden, Hari Balakrishnan, Nirmesh Malviya, and Sejoon Lim.

Code for map matching and delay prediction was developed by Arvind Thiagarajan, Katrina LaCurts, Lenin Sivalingam, and Sam Madden.

Street maps are provided by openstreetmap.org.