When assessing the sustainability of a vehicle it is important to distinguish between “Sustainable” and “Potentially Sustainable”. Well, buses could be sustainable, but because the vast majority of people are reluctant to use them, they cannot manifest their sustainability. On the contrary, in certain circumstances, they are less or even far less sustainable than single-occupancy cars, especially in off-peak hours when they have to run according to their schedule even if nearly (or literally) empty.
Nymbel PODs are, by default, single-occupancy. The prototype we are building weighs ~220 kg. Adding the 120 kg of the passenger and his 60kg baggage, the POD will not exceed 400 kg. There are also special PODs designed for parents with kids under 10 and for wheelchair users accompanied by their chaperone. These versions have limited baggage storage, and they will never exceed 400 kg.
Nymbel PODs are available in every station 24/7/365, and they set off as soon as the user sits down. With one passenger on board, Nymbel reaches 100% occupancy. Deadhead trips in the Nymbel system occur in very rare situations and on very short distances (less than 1/2 miles).
To get the same energy efficiency as a Nymbel POD, a bus must carry 39-40 passengers. The current average bus occupancy is around 11.5.
Case study Bus vs Nymbel between Leeds and Huddersfield
There are 76 bus stops on the 20.5-mile distance between Leeds and Huddersfield. The Arriva Double-decker buses run at intervals of 15-20 minutes. If filled at capacity, buses could transport 80 people, having a capacity of 5.3 people/minute or 320 people/hour.
Nymbel PODs can only carry one person, but they can do so every 2 seconds, achieving a capacity of 30 people/minute or 1800 people/hour. While buses must do their trip according to the schedule even if they have no passengers, Nymbel PODs only set off if they are 100% occupied, saving energy, wear and tear, and preventing unnecessary traffic overcrowding.
The public space-use reduction is 7.2x, and the tracks must only withstand 400 kg (compared to 18,800 kg of a bus filled at capacity), allowing for its infrastructure to be elevated yet relatively inexpensive.
Emissions (Energy) wise, a Nymbel POD’s energy consumption per passenger equates to that of a 50% loaded bus. Buses with over 40 people are more energy efficient than Nymbel PODs. However, the current average bus occupancy is around 11.5, which is way below Nymbel’s efficiency.
The journey time is reduced to about a quarter, not to mention that there are no schedules to stick to, no waiting time, no crowding with their germs and viruses, and no intermediary stops. Moreover, buses operate on fixed routes, while Nymbel is a spiderweb-like network that can take you from anywhere to anywhere throughout it, without needing to change vehicles.
Buses are a burden for local budgets. First, they need to be purchased and then in order to make them affordable and attractive, they must be subsidised. Nymbel, however, thanks to its energy, resource, space, and time efficiency is regenerative (not just profitable) and self-sufficient and doesn’t require public money to be implemented or operated. Local budget involvement is welcome but not compulsory.