GPS-Based Road Traffic Monitoring System - A Study of the Cell Phone-Based Model

At present, most road traffic monitoring systems use sensors and video cameras to check the speed of vehicles and to take snapshots of vehicles that violate signals. However, the cost of this equipment has restricted the current video camera-based road traffic monitoring systems to certain very important areas and important highway intersections - where there are greater possibilities of traffic congestion and accidents.

The government is willing to cut down the costs of the "sensor and video camera based road traffic monitoring system" so that it can implement it widely. To achieve this, it has permitted several research groups and telecom companies to come up with a model- both practical and cost effective- covering large areas (not only certain portions of the city and highway intersections). There are several research projects going on, some using government grants and some on their own – conducted by telecom giants such as Nokia, UTStarcom, and others.

The common point in all these researches is that almost all of them are considering GPS-based road traffic monitoring system to bring down the overall costs of maintenance because the costs of the GPS devices are low and are showing a further downward trend. Almonst every person with a vehicle has a GPS device or can afford a GPS device for vehicles, which means that the stage is already set. We just need to put the different components in place so that the desired GPS-based road traffic monitoring system can be put into place.

The following section discusses the cost effective model of GPS based road traffic monitoring system proposed by Nokia, a leading telecom company.

The model for GPS-based road traffic monitoring system presented by Nokia is based on the fact that almost every vehicle driver already has a cell phone. If the model is implemented, the cell phones can be upgraded to ones that contain GPS units if the existing ones do not have one already. The basic concept of this model is to trace "each" vehicle using the signals sent out by the GPS unit in the cell phone. The model claims to monitor real time flow of traffic using the GPS enabled cell phones while securing the privacy of cell phone users.

The model suggested by Nokia for GPS based road traffic monitoring system employs use of: 1) GPS enabled cellular handsets; 2) a central server for each area; 3) the Internet; and, 4) a unit to view the traffic condition. This unit can be the cell phone itself, a GPS unit, or any other device capable of connecting to the Internet and displaying the traffic conditions.

Each area under observation will have a central server of its own, thereby using several servers to cover a larger area. These central servers can be integrated using wireless connections to create a network that covers an entire city.

Each car will be equipped with a GPS-enabled mobile phone. The GPS unit will contain some software that will send signals carrying data on the vehicle's speed and location to the central server for that area. With all vehicles in an area sending signals to the central server, there will be ample data to compute the traffic conditions of that area. Once computed, the results will be uploaded to the Internet in form of images (graphs or charts). This information can be viewed by anyone on his/her cell phones or any other device able to browse the Internet. The best thing about this model is that both drivers and the traffic police can view the traffic conditions in real-time with a delay of only few milliseconds.

While speaking on the model's feasibility, a Nokia staffer says, "Enlisting GPS-equipped cell phones into traffic monitoring systems could help provide information on everything from multiple side-street routes in urban areas to hazardous driving conditions or accidents on vast stretches of rural roads. GPS-based systems can pinpoint a car’s location with an accuracy of a few meters and calculate traveling speed to within three miles per hour." This is quite true but there are certain obstacles that will have to be considered for implementing this model of GPS based road traffic monitoring system.

Roping in Cell Phone Service Providers

The first and foremost problem that may interfere with Nokia's GPS-based road traffic monitoring system is the fact that different people use different service providers for their cell phones. As all the residents of US cannot be persuaded to use the same service provider, all the different service providers in US will have to be roped in so that the model works offering full data on vehicle movements.

Even if one service provider backs out, the model will yield partial results. However, Quinn Jacobson, Nokia Research Center's research leader is confident that there will be no problem as these service providers will only benefit from being part of the GPS-based road traffic monitoring system. Also, drivers will not let the service providers back out as there are additional benefits to the GPS-based road traffic system than just traffic updates. According to Jacobson, "Integration of traffic information with functions such as calendar and online timetables means that the mobile device can act as personal travel planner. With the increasing number of vehicles, a proper road traffic monitoring system will help drivers save time and precious fuel by taking alternate routes based on real time traffic information."

Bandwidth Problem

Assuming that the cell phones in Nokia's model of GPS-based road traffic monitoring system send out signals every three seconds, the system will require a huge bandwidth considering the number of cell phones active at any given point of time. Alexander Bayen, professor of systems engineering at Berkeley’s California Center (the institute is also part of Nokia's GPS traffic monitoring research), says that they are working on a solution to find an optimum subset of the entire data so that the model does not need such a huge bandwidth. However, I could not get any clue anywhere as to what kind of solution they are considering.

User Privacy: A Major Problem

Most of the users of the cell phones will not want their phones to send out signals indicating their whereabouts that can be intercepted by unwanted sources, too. According to Jacobson, if users are not willing, they can turn off the GPS feed in the cell phone. This will not affect the proposed GPS-based road traffic monitoring system as it will disassociate the data with the cell phone and use it anonymously employing SSL (bank type encryption) so that the data is not used by anyone else, thereby protecting the privacy of the cell phone owner. Read our article on GPS Cellphone - Ethics Violations.

Unwilling Users – People not Willing to Participate in the Monitoring System

There will be drivers who will not be willing to contribute. They may not use GPS-based cell phones or may turn their GPS off. There will be a hard time persuading such drivers. However, considering the benefits of this GPS-based road traffic monitoring system, the percentage of such people will be very low. The results of computing at the central server will not be affected, so the servers will still be able to upload real-time traffic information to the Internet.

I also went through some other proposed models for GPS based road traffic monitoring systems, out of which, one was more stable than the Nokia model but it was not as cost effective as the model discussed here.