Tilting three- and four-wheelers make a lot of sense - they're almost as narrow and light as motorcycles, and perhaps even more maneuverable, but they offer enormous amounts of grip and stability. There's so many new narrow track vehicle designs sprouting up all over the world right now that it's easy to see them becoming a significant part of the commuting mix in the congested cities of tomorrow. So here's three new designs we spotted at EICMA Milan - one electric four wheeler, a petrol powered three wheeler and an aggressively styled four wheel tilter that seems to have off-road ambitions.

Tilting narrow-track vehicles: the state of play

There's no getting around the fact that our urban infrastructure can only deal with a certain number of people. The roads servicing many cities, originally built in the days of horses and carts, are regularly grinding to a standstill under the weight of rapid urbanization and population growth.

The fact is, commuting in cars is a gigantically inefficient use of space - particularly when you can take a look around at the dour faces of peak hour and notice that the vast majority of cars only have one person in them. And as space continues to tighten, and populations continue to move into cities, the problem can only escalate.

You can look to Asia for solutions - the continent is full of cities where people have adapted to living in far higher concentrations than most western nations. And the first thing you notice about Asian traffic (apart from the complete chaos, depending on where you are) is that small, efficient motorcycles rule the roads.

It's interesting to note that governments in Europe, Australia and elsewhere seem more interested in deterring motorcycle use than encouraging it - but the simple fact is that in vastly congested cities, a bike can get places quicker, fit through spaces that stop cars dead, and generally park much closer to the destination than a tonne of metal with four doors.

For many people, the issue is safety - especially in wet weather. And that's where the reasonably new class of tilting three and four wheelers comes in. When Piaggio got to the market first with the MP3, it completely sold me on the concept: a tilting vehicle with two front wheels is simply much harder to crash than a motorcycle - without adding a huge amount of technical complexity or width to the vehicle.

They're also a huge amount of fun to ride - but while they haven't really taken the market by storm yet, it's clear that a lot of companies see huge potential in the future, because they're popping up everywhere! Nissan's Land Glider (pictured above), the 4MC, the Sidam Xnovo, VentureOne (now Persu) and the Naro tilting car all show different interpretations of how it might end up happening, and sit at very different points on the scale between car and motorcycle.

And at EICMA Milan, we saw three new implementations of the tilting narrow track vehicle concept that tickled our fancy: the Swaygo 575 EVR-1, the Quadro 350D and the funky Quadro Parkour.

The Swaygo 575 EVR-1

South African company Swaygo has been making four-wheeler prototypes since 2006, but the fully electric 575 EVR-1 looks like the first product the company will bring to market.

The EVR-1 takes advantage of the broader body and carrying capacity of the 4-wheel platform to pack the chassis with battery cells. As such, it's got an "effective range that exceeds 100 km (62 miles)" - although such claims really don't mean much yet in the electric vehicle market, with no standards to go by and a wild variation in battery range depending on how far you twist the throttle.

Twin electric motors are mounted in the rear wheel hubs, allowing direct drive as well as regenerative braking.

Perhaps the most interesting part of the Swaygo's design is that each front wheel is mounted on a separate, short pair of forks, and each rear wheel is suspended by its own shock and miniature swing-arm. It's unclear how the front wheels are connected, but there is a tilt locking mechanism for parking or sitting around at the lights with your feet up - and it's operated by a "vertical center disk brake." So... A bit of a mystery, that process.

Being a little beefier than your typical tilting three wheeler, and carrying some 80kg worth of battery packs for a total kerb weight of 290 kg, the Swaygo comes complete with what I imagine would be a very handy reverse gear - and the single forward gear is good for a maximum of 105 km/h (65 mph) .

Enquiries can be made at the Swaygo website.

The Quadro 350D

Italy's Quadro is working on bringing a number of 3- and 4-wheeled tilters to the market, but the first to look production ready is the 350D.

A conventionally shaped maxi scooter with an aggressive frontal design, a 350cc motor and two front wheels, the 350D could easily slip unnoticed into a Gilera Fuoco procession. But the front suspension and tilting mechanism looks quite different. Where the Piaggio's tilt mechanism is all managed closer to the headstock, the Quadro system sits quite low to the ground, almost acting as a flexible axle between the two front wheels.

Suspension struts on either side appear to give the front wheels three shock absorbers between them, and a lock-off valve in the middle provides a hydraulic tilt lock. Either way, the system delivers the same claimed 40-degree lean angle as the Piaggio/Gilera platform - which is more than enough for a good time on the road, let alone happy, safe commuting.

The 350D has a cigarette lighter attachment for mobile phone charging, and enough underseat storage for two full faced helmets.

More information at the Quadro website.

Quadro 4D Parkour

Also looking fairly close to production (although not hugely different from Quadro's standard 4D 4-wheeler was the Parkour, a tilting 4-wheeler with twin driven rear wheels, a fairly aggressive paint job and semi-offroad tyres.

Anyone who's ridden a tilting 3- or 4-wheeler can attest that you really don't lose a lot of traction or stability when you take these things off the paved road - I was stunned at how grippy and planted the MP3 felt when I went weaving back and forth on the grass.

The Parkour, named for the sport of urban obstacle-jumping, seems to want to capitalize on this. But while it looks pretty cool, and might be marginally better than its brethren on dirt, it doesn't appear to have longer travel suspension, the low front tilt mechanism will raise ground clearance issues and at the end of the day it's probably way too heavy for serious offloading.

Still, as a light offroader, it might have a bit to offer ... and it'd be interesting to see the effect of sticking one wheel into a rut and seeing where you ended up.

As I say, tilting triples and quads are starting to pop up all over the place. It's hard to see them making a big dent in American, UK or Australian markets in the short term - they're still a bit 'uncool' for the riding communities in these countries where riding is more of a recreational lifestyle choice than a commuting option. But it'll be very interesting to see how they take off as a safer option on the congested roads of Asia, or the cobblestones of Europe. And in the longer term, it'll be fascinating to see if they end up becoming a larger part of the commuting mix here at home.

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