New York City probably has the most famous taxi cab network in the world, but also one that is rather controversial due to the bizarre regulations and outrageous license costs. As they are quite ubiquitous, they are also a major urban pollutant, which are holding back the city's efforts to reach its own environmental goals. We set out to design a conceptual system which could function in this urban jungle, in terms of technical requirements, as well as aesthetically, ecologically and economically on the long term.
This is a study project on electric vehicle system design. The focus of the project was on dimensioning the drive train, adjusting the entire system so it could function in the New York infrastructure and taxi system and fitting both the passenger’s- and driver’s needs while remaining as small as possible to increase energy efficiency. While we have looked briefly into various grades of automation, the project brief was clear about the exclusion of autonomous solutions, so the concepts are all piloted by a human driver.
First, we analysed a large amount of data on New York taxi rides to find usage patterns like typical distances, locations, passenger amounts, busy times and relations between those numbers. Other contextual constraints like existing EV infrastructure, grid load, incentives, working hours, highway locations, the controversial medallion system and the cultural aspects around it were examined and considered. One challenge is wheelchair accessibility, which we decided relatively early on to solve by keeping a portion of the current minivans in the fleet, as making all cabs wheelchair accessible would have severe consequences on the size and therefore a reduction of energy efficiency in most rides.
3 initial concepts were created to explore possibilities of creating a compact vehicle that still looks attractive. On top of that we took on two other challenges: One, we wanted to clearly communicate that it is an electric vehicle and communicate its current charge, so you won’t be disappointed when hailing an almost discharged cab when commuting to the airport. Secondly, we also wanted to address the health issue, as we found various studies implying that being a cab driver is exceptionally unhealthy, especially due to the long ours of static sitting and breathing city smog.
For this first concept, we kept to a relatively “standard” look, derived from current automotive design, with a somewhat sporty urban appearance. The battery power is represented by a “draining” taxi sign, and by moving the engine to the back of the vehicle, the front bonnet can be used as luggage space while also serving as a crease area, while the back can decrease in size. In this more conservative concept, improvements regarding health are not too radical and are presented in the form of nudges in the interface, like notifying locations for a healthy lunch or suggesting the driver to go for a run in a nearby park when he takes a break.
The second concept has a little bit more recognisable silhouette and is built up of circular shapes and horizontal lines that are a subtle hint to the iconic Ford Crown Victoria cabs. A lot of glass is used in the greenhouse to give a more spacious feel to compensate for the smaller size, and gives the driver both a better overview of the city traffic as well as the positive psychological effects of outdoor light. The visual communication is done through a lighting charge bar underneath the doors, and a taxi sign lighting up on the place where one would expect the grill on a conventional car (there is still an air duct for cooling and ventilation underneath the sign, however it is visually not as present). For health improvement, there is care to be taken in the ventilation system, which can filter the air and has feedback through monitoring the air composition, the windows are operated manually so the driver will be less inclined to open the window and more so to turn up the ventilation, and a massage chair is added to keep the drivers’ muscles more flexible, while also maintaining a more active position in the design of the chair.
The third concept is most disruptive, and is completely based around the concept of more healthy driving. Instead of using a conventional automotive chair, the driver sits or stands in a console with large degrees of freedom, almost like an exoskeleton. By adjusting the mechanical resistance and response, the driver can basically set up a training program while operating the taxi cab. Other benefits of this standing position is that the driver has a higher vantage point and can look round easier, with a cabin designed to have minimal obstruction of sight, and with the semi-standing position, the driver takes up less space in the horizontal plane, creating a compact “stubby” minivan that still has the height to transport for example wheelchair users.
Finally, the second concept was used as a base with some additions from the other two concepts, most notably the added sign on the roof from concept #1, as it also needed to be visible when another car is in front of the vehicle. Even though the third concept has some interesting benefits, it was considered not safe enough because the new interaction would probably have a steep learning curve (which also makes it expensive) and the reaction times are probably not fast enough, however when given more time it would have been an interesting avenue to explore through testing.
One of the challenges was finding the most cost-efficient way to charge the car. We first considered existing charging solutions, ranging from smart charging (which charges the battery according to grid usage to function as a buffer) to fast charging (which uses extra high currents), however even the latter was simply not economically feasible when considering the ridiculous price of the medallion licenses (one license for one car costs around a million USD). Therefore, we also explored two concepts for exchangeable batteries. The first one is this manual charging station, where batteries are rolled out of the car onto a rack which then folds up pneumatically and can be shifted into the charging bay, a system which is intended to both save space and the driver’s back. An additional benefit is that these charging batteries can be used like a smart charging car, but without needing a separate medallion licence.
The second battery charging concept is the most complicated, yet surprisingly enough, through the time saved it is highly likely that this would be the cheapest solution when strategically placed, even when considering used space, development costs, building costs and buying of the robots & tooling. The system consists of a robotic arm that is located underneath a garage floor and surrounded by charging bays. When a car passes over, the robotic arm can take out the battery from underneath, put it in an empty charger and pick a full battery to replace it, and the car can continue.
We created an interactive model to estimate specifications in relation to requirement parameters, such as maximum grade and passenger configuration.
The interior was also briefly looked at, and specifications about auxiliary user systems like the car control interface, air conditioning, payment system, communication, lighting and interior power management were determined according to system specifications and user requirements, as well as usability issues like accessibility and audio requirements for sounds that the car should make to make its presence obvious for safety reasons. A quick mock-up of a possible dashboard configuration shows that a lot of the controls are on the steering wheel, and the displays are meant to be clear and without clutter, while displaying all needed information.
