From the Piaggio MP3 to the Toyota i-Road: The Reemergence of the Man-wide Car

I work for a high-tech aerospace company. You would think with all the techie engineers in the place, there would be some interesting vehicles in the parking lot. Except for one vehicle, all the others are pretty mundane. The exception is a Piaggio MP3 three-wheel leaning scooter. It belongs to one of our technicians and, with more enthusiasm than he may feel is justified, I tell him he is riding the future.

The extra wheel significantly increases stopping performance and the ability to lean allows the MP3 to be controlled when the wheels break free on slippery surfaces. This is opposed  to the vehicle falling over if it had just two wheels. While road testing the new 500cc version of the MP3 LT, a Cycle World reviewer dropped (out-distanced) a rider on a BMW R1200GS on a snow-slicked section of curved Berlin highway, a clear indication of the performance potential of a leaning trike. The LT stands for large track, an acknowledgement of the front wheel spacing being over 650mm. In Europe and the UK, if a trike has a track wider than 650mm, it is consider a car and can be ridden without a cycle license or a helmet. Only an auto driver’s license is required.

By making the MP3-LT controllable on slippery surfaces, Piaggio has taken a huge step forward to producing an all-weather scooter.  And with top speed in excess of 80mph and a fuel economy of 60mpg, is offers an attractive commuting alternative to an auto. It just needs a body and it could be considered an all weather scooter, or in a broader sense, a man-wide vehicle or MWV.

In a University of Michigan sustainability study for 2010, vehicle occupancy was calculated to be 1.55 persons per vehicle. That means that for most of our trips and the majority of vehicles there just one occupant in the auto. It is clear that one person in a four-person vehicle is moving too much mass, pushing too much air, burning too much fuel  and taking up too much space.

Most trips could be accomplished using a vehicle tailored to one person or two persons in tandem, a man-wide car. Since the vehicle is lighter and more aerodynamic (less frontal area), fuel consumption could be significantly reduced. And the smaller vehicle size would allow more vehicles to occupy the same lane width as a normal-width vehicle.

The investigations into MWVs by large auto companies are not new. Honda had its EP-X which seated two.

Volkswagen had its L1 which also seated two.

And general motors had its Lean Machine which only sat one.

But only the Lean Machine approximated the width of a motor cycle, 850mm (33.5”), with its 915mm width. Narrow-track three and four-wheel vehicles risk overturning when cornering. Allowing the vehicle to lean like a motorcycle provides  for dynamic stability  and allows the width to remain narrow without the risk of overturning. The Lean Machine was narrower than these other attempts because it could lean.

http://lefthandedcyclist.blogspot.com/2012/02/drymer-and-varna-lean-forward.html

Now both Toyota and Nissan have MWVs that utilize leaning to reduce the vehicle width. Both are completely electric powered.

The Nissan Land Glider uses four wheels that are articulated allowing the vehicle to lean. At 1100mm width, the Glider is wider than a motorcycle but still significantly narrower than a Smart Car’s 1550mm width. The glider seats two in tandem.

 The Toyota i-Road is also a dual occupant vehicle that is narrower than the Glider at 850mm, mostly due to the layout (like the Lean Machine) where the single wheel does the steering and thus doesn’t require the width that two-wheel steering does. What is unusual about the i-Road is the single-steered wheel is in the rear. If the instability issues associated with rear-wheel steering can be overcome, (see below),

http://lefthandedcyclist.blogspot.com/2012/01/bucky-and-urbee.html

this layout is ideal for packaging. Because the front wheels incorporate the electric-drive motors there is room between them for the driver while maintaining minimum vehicle width and the steered wheel fits easily in the width of the vehicle. 

I attempted to use this layout for the initial design approach of my EcoVia commuter trike, but could not come up with a mechanism for stable control of the steering and leaning that functioned at anything  but low speeds.

http://lefthandedcyclist.blogspot.com/2012_08_01_archive.html

Fortunately, the i-Road can utilize active electronic control to insure stability. The i-Road’s top speed is less than 40mph so it is not suited for highway use. What is encouraging is that the project has graduated to the consumer test phase where 20 Japanese drivers will get to evaluate the i-Road under real-world driving conditions.

Probably the most unusual approach to developing a MWV is the C1 from Lit Motors. It uses two gyroscopes to balance the two wheel vehicle. Gyro-stabilized two-wheel vehicles have been around since the dawn of the automobile, but in this case, since the vehicle is all electric, power is available to keep the gyros running temporarily even when the drive motor is turned off. It also features twin retractable support legs that hold the vehicle up when permanently stopped. The amount of balance torque generated by the gyros is impressive and will insure the vehicle stays upright during collisions. It will seat two people. Since it has only two wheels, it will require a motorcycle license to drive.

The i-Road and the C1 are essentially all-weather motorcycles, but for the increased cost, buyers will require significantly more crash protection than your average motorcycle. Providing this will require some creative use of materials and structures to prevent significantly increasing size or weight.

If MWVs become numerous, they may cause changes in highway infrastructure. Single wide highway lanes could be turned into two narrow lanes, and therefore improve traffic throughput. This would require recognition that the smaller vehicles merit special consideration which may be a difficult sell to the general public.

I rented an original Honda Insight when my car was being serviced. Since the car was more narrow that what I had been used to, sitting in the car in my driveway I could imagine the vehicle was only one-seat wide. As long as I am warm and dry and can safely maintain highway speeds, I could live with a vehicle like that.

Hopefully, in the not too distant future, there may be mature MWVs parked in the lot where I work. Maybe one will be mine.

Hephaestus