For historical reasons, wireless systems for use in the transportation sector have taken a separate path for technology development. This divergence no longer makes sense. Every other sector in the economy is finding secure, reliable, and economical systems that use internet-protocol and are highly compatible. Continued insistence on separate radio frequencies, closed networks, and obscure proprietary standards mean that technology investments in transportation don’t take advantage of low-cost high-volume components developed for the consumer market or advances in communications hardware and routing software.

Congestion charging cameras in London. Photo by jeroen020 on flickr.

Rest-of-the-World Trends: Open networks, Device Convergence, Open Standards, Extensible/Interoperable, Consumer products/parts (high volume, low cost), Redundant networks base, Robustness/Redundancy

Versus

Intelligent Transportation Systems: Closed network, DSRC (Dedicated Short Range Communications), Single-purpose devices, Proprietary, inflexible, Proprietary lock-in, high cost, path dependency, Can’t leverage others’ investment, Centralized command & control (single points of failure)

Below are my recommendations in priority order. Wireless infrastructure investments for congestion pricing, open-road tolling, and road pricing should be:

• Open networks (the data transmission required for user-fees is very small, meaning that a huge amount of excess capacity in these networks is available and should be made available to the public given that this infrastructure is being paid for with taxpayer dollars).

• Open standards (making these networks open is only interesting and useful to others if open standards are used).

• A mesh network be employed.

• An open source mesh network be employed.

• An extensible/interoperable network should be deployed (creating opportunities for user-driven innovation, add-ons — think Google open API model)

What would this system look like? What are the benefits of a system so configured?

Imagine a mesh “white box” in every car that travels through the city. The device would cost between $50-$75 in the volumes needed and be built using low-cost, widely available standard hardware components and open source software. Each car would become a node in a dynamic mesh network, routing and repeating packets of data. People who purchase and install the devices in their cars can be given the first $100-$150 in congestion fees for free. System security requirements would be no different than any other wireless infrastructure, and preserving ample bandwidth for the purpose of collecting fees can be assured. Implementers would need only be responsible for providing key backhaul nodes (e.g., at critical intersections, exits, etc.) while end-users would drive the node density necessary to expand the network. The implications:

• The amount of capital required to implement, maintain, and extend a congestion pricing system is reduced in several ways:
  • Congestion pricing hardware, and the majority of the wireless infrastructure, is financed and installed by end users.
  • Less infrastructure installed means less to maintain
  • This dramatically reduces the debt burden required and the cost of financing it.
  • Because the devices are self-configuring, there are reduced engineering costs.
  • Reduced installation costs (simply plug them into the vehicles).
  • The system can come online and be operational in less time than a system of tags and beacons, and therefore the free premium given to drivers would be a net revenue wash.
  • Very low on-going communications costs because the system relies primarily on free peer-to-peer data transmission.

• System redundancy is inherent in such a network. There would be no single point of failure and no need for redundant systems to be designed and included.

• Car location and charging could be based on GPS position or triangulation of vehicles relative to other vehicle and gateways (where the data enters the internet) similar to systems used by Loki and TomTom. [A discussion of protecting locational privacy is discussed in another paper.]

• An in-vehicle mesh-based system allows infinite flexibility in the congestion pricing system.

• • The initial pricing cordon chosen by the city can be changed over time without additional on-street hardware investment (At considerable expense, London expanded its cordon from the CBD to a larger section of London after 4 years).
  • A dynamic real-time congestion pricing could be implemented covering all city streets, eliminating undesirable edge effects created by a cordon, charging based on actual congestion, increasing public perception of system fairness (charges based on real congestion, not arbitrary geography)

• Enforcement would not be based on cameras and license plate photography, but rather on-the-ground enforcement officials determining whether individual cars in their proximity have an active device. High fines/tickets can be given to those vehicles without the device that are within the congestion pricing zone.

• “Tourist” vehicles passing through the congestion pricing zone can pick up a device at gas stations, highway rest areas, and convenience stores. The cost of the device would be required as a deposit (in cash or by credit card) with an additional amount paid for anticipated fees. On exiting the congestion pricing zone, these devices can be returned with the deposit and unused funds returned to the driver. Those who choose this system would not be eligible for locational privacy, nor the free service premium given to those individuals who buy the device outright.

• Facilitates layering of additional services and applications on a de-prioritized basis vis-a-vis congestion pricing/network data, creating additional potential revenue sources and value to users (e.g., internet access, social networking software, geolocational advertising, real-time traffic/congestion data for drivers).

• Can be utilized to send emergency communications messages to all cars, cars in specific areas, etc.

There are considerable positive “externalities” that this system would give to the city that adopts it:

• Because the network is open to all, within the congestion pricing zone, Manhattan would effectively be one dynamic wireless hotspot
• A ubiquitous wireless network throughout the city, open to all, will generate an untolled/untold amount of innovation and economic development.
• Over time one can anticipate other devices joining the mesh created by the vehicles. Each one of these devices leverages the existing investment of all the previous devices, contributes to the mesh, and gets the full advantages of zero cost peer-to-peer communication within the city. These new devices might be those purchased by other city departments (homeland security, police, emergency vehicles, education, health, social services), or by city residents (mesh-enabled laptops, cell phones, PDAs). The result is a scalable, resilient communications system. Different user classes and/or prioritization schemata can be utilized to ensure critical communications have access to this robust and redundant communications infrastructure.
• An open tech system avoids path dependencies and ensures maximum extensibility during a time of rapid technological innovation and evolution.