A real-world logic and numbering-system dilemma:

I work at a private service ambulance company. We currently have 9 stations with wheelchair vans, medic trucks, and up to 9 BLS trucks *per station*.

We’re looking to add a tenth station and a tenth truck, with long-term plans to add more of each. The problem is that our current numbering system will not accomodate these changes.

Our current system:

Wheelchair trucks start with a 1 and are numbered sequentially: 101, 102, 103, etc.

BLS trucks whose headquarters are at, for example, station 2, start with a 2 followed by two digits: 228, 225, 210, etc.

Medic trucks whos headquarters are at, for example, station 9, start with an M, a 9, and then one digit: M91, etc.

Thrown into the mix is an altogether different numbering system of our vehicles themselves, which are assigned by the state in four-digit fashion with apparently random digits, that we have no control over. Thus, we would like to stay away from four-digit numbering for our trucks.

While future-proofing may be impossible, we’d like to future-resist as much as we can. We’ve thrown a few ideas around, but none have really struck our fancy.

Any ideas?