Synergies Between Driverless Transit and Driverless Cars
Developments of driverless transit on guideways (Automated Transit Networks – ATN) and driverless cars (DLC) can benefit from each other in several ways.
Car developments are enabled by massive investments, bringing new sensors, advanced image processing and economies of scale. Car industries, by virtue of their size, gain political support, which helps in negotiating new legislation. So far DLCs are still experimental, being tested on public roads by local permissions only. Until DLCs eventually become legal on roads they can be introduced on guideways or other dedicated rights-of-way.
The ATN industry has 40 years of accident-free driverless operation, approved certifications, track records for safety and reliability over 99.5 %. ATNs use proven control systems, empty vehicle management, ride-sharing strategies and intersection controls, which can all be applied to DLCs. As an example, ATN controllers allocate passage times to individual oncoming vehicles so that they can pass through intersections safely at speed.
Even when DLCs have been introduced, guideways or more road-space will be needed in places where roads are congested. Cars can go on guideways and ATNs can go off guideway (Dual-Mode). The distinction between DLCs and ATNs will be blurred. Similarly the distinction between private and public transport was blurred by the introduction of shared rides and shared-use cars, whether private or publicly owned.
With mixed-use guideways and roads, regulations of DLCs and ATNs must be harmonized. Present ATN regulations ensure levels of safety ten times higher than those of present car traffic. New systems are required to be at least as safe as existing modes – for ATNs the comparison has been with the safety of rail transit.
What safety levels will be required for DLCs – the same as manual cars (easy) or as safe as ATNs? The car industry has no incentive to take risks so they will probably design for safe headways between vehicles, whether or not this is mandated.
Even with V2V communication, safe headways may lead to reduced capacity and hence the need for more roads or guideways. Ride-sharing will be necessary to compensate for longer headways between cars. Every ATN system already applies ride-sharing and have done so since day 1.
It is time for legislators to catch up with technical developments and harmonize safety regulations for driverless vehicles on roads and/or guideways.
Rendering: Robert Jacobsson