Alternatives that provide major structures in an arterial network are not acceptable for amenity because of visual blight and because of reduction of road capacity. Alternatives that do not attract sufficient mode change away from cars are not acceptable for amenity, despite the expedient current practice. Both these items should be fatal flaws. Alternatives that do not make a profit are not financially viable, such that standards that apply for businesses should also rule them out, despite our current approach for public transport. Alternatives that lower the level of transport service are not acceptable. All alternatives except suspended podcars are therefore ruled out.
The objectives for transport of crashes, assaults, amenity, congestion, trip time, revenue, jobs, reliability, CO2, and rural service have been previously discussed on this site, together with the requirements for achieving each objective. The objective of rural service was not met and requires a faster solution.
Programs for each of the available transport modes of monorail, car sharing, driverless-cars, public transport, road pricing, better roads, supported podcars, aerial podcars, and drones have been previously described on this site, together with an evaluation of their impacts.
A realistic analysis of freight has not been included but aerial podcars can make some contribution and the conclusion is unlikely to be changed by its addition.