City traffic

City traffic is a problem around the world. It is undeniably attractive that individuals should have transport that gives personal freedom, but the current system of cars does not work well and cannot scale to serve everybody. Can we fix this?

Electric vehicles hold a lot of promise. Of course they are low pollution and potentially efficient, but one big advantage seldom discussed is they are much more precise. Regulating an IC engine is messy and slow. You get at best a tenth of a second lag on an accelerator plus the transmission gears and torque converter add imprecision. An electric motor, by contrast, can be controlled to the millisecond and is potentially closely coupled to a wheel. This means that electric cars in principle can be driven in close formation convoys and in efficient sequencing down streets and across intersections without stopping. Of course, you would need computer control since this is beyond human capabilities, but most drivers would probably be happy to put the daily commute on autopilot if it would be faster and predictable.

The payoff for a city is that much less of its valuable space needs to be invested in roads, and the existing rights of way could carry increasing traffic without the expensive and near impossible politics of building new roads or widening existing.

Of course, electric vehicles are tough to build and battery technology could take years or decades to become practical. But there is an alternative way to go, combined with batteries or hybrid drive: electrify the roads. Why not provide electric power through the roadway to participating cars? It would cost, but it would upgrade the capital value of the city and probably pay for itself in a few years so it is an interesting path to explore.

You don't need to put rails in the road. Keep your rubber tires and asphalt surface, but experiment with embedding conductive materials in the formulation of both. If the front and back tires connect as a circuit (a configuration that supports bikes as well as cars) then you can probably get a couple of kilowatts per wheel pair which is enough to sustain urban speeds.

How to avoid electrocuting pedestrians, and how to make the front and back tires get opposite parts of the circuit? Well, you make the system smart. The car would need to signal the road through the wheels (or possibly through separate sensors) so computers controlling the road know the vehicle, the speed, and where each tire is. A pedestrian does not signal the road nor come close enough to a moving car to be included in the active circuit, so to someone walking the road is just a safe paved surface.

The vehicle could then be lightweight since it does not need onboard battery for long range, with current lithium batteries a 50 lb set would allow a half ton car easy range in the suburbs to and from the core electrified network plus boost for hills and acceleration or across gaps in the road supplies. Since there is no heavy IC engine or transmission, with a powerful electric motor under 100 lb, making a 2 person vehicle with luggage space with a loaded weight in the half ton range seems quite reasonable.

Of course the roads would be expensive to build, you would probably need to prefabricate the surface elements and lay them out. However, many cities have property values of $1M per 100 ft or often much higher, so it does not seem at all impossible that something on the order of $100k of equipment might be embedded in the road to maximize traffic flow while minimizing vehicle costs, dangers, and pollution.

Our cities today are pretty stale in terms of transportation. We could transform them and not necessarily by forcing everyone into shared, inflexible public transport systems. We are by no means at the end of the road for personal automobiles.

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