Now that the London Congestion Charging zone has expanded westward, the search for ways to avoid coughing up £8 for slipping a tyre into the controlled zone has intensified. And we have finally spotted a vehicle that fits the motor tricycle exemption from the charge (see the earlier post Will the congestion charge make you go Ape? for details) .

You don’t have to pay if your “car” has three wheels and is less than a metre wide and less than two metres long, a peculiar exemption that seemed to fit no vehicles at all.

Well it does fit the T3 Series of patrol trikes from T3 Motion. These look a bit like a Segway Human Transporter without the stupid/clever self-balancing complication - instead the T3 relies on a tried and test, old-fashioned third wheel instead of gyroscopic silliness.

A T3 uses a pair of lithium-ion batteries to give a maximum quoted range of 75 miles and a maximum speed of 25 mph (probably not both at the same time, mind). Plus, because it is aimed at security workers, it has a siren and flashing strobe lights to help encourage people to get out the of the way while you’re commuting.

The snag? Well, it costs about $6,200 (£3,200) for the trike plus $1,800 (£930) for the long-range batteries. Plus you get wet when it rains. And you may get the odd stare.