When Elon Musk finally emerged from pulling his and finally delivered his new , it proved to be full of some interesting ideas. Of those ideas, I think the plan for Tesla to build a semi heavy-duty truck is by far the smartest, and offers some really interesting possibilities.

The idea for Tesla to build a large, long-haul trucking vehicle came from the section of the Master Plan modestly titled “Expand to Cover the Major Forms of Terrestrial Transport.”Interestingly, Musk didn’t mention any plans for shoes or skateboards, but did have this to say, emphasis mine:

In addition to consumer vehicles, there are two other types of electric vehicle needed: heavy-duty trucks and high passenger-density urban transport. Both are in the early stages of development at Tesla and should be ready for unveiling next year.

Here, listen to this to get you in the mood to think about big trucks:

Yeah, that’s the stuff.

An all-electric semi truck with some provision for some level of autonomy actually makes a lot of sense. Tesla hasn’t released any details about what their Tesla Semi might look like or how it may be designed, but I think we can make some educated guesses here.

First, for the overall look of the truck, I’d expect something to have some aesthetic ties to the Tesla corporate grille-less face, but I think the real look will be defined by aerodynamics.

A big rig is a tricky beast, aerodynamically, and Tesla’s design will be restricted by the need to accommodate conventional trailer rigs and standard shipping containers. A lot of work and research has been happening lately involving improving the aerodynamics of trailers, which is why you see so many trucks on the road now with odd-looking aero flaps and extensions on their trailers.

Tesla’s semi truck would need to be compatible with all types of trailers, and their cab design’s scale will be dictated by established standards as well. The look will be sleek and aerodynamic, likely dramatically more than current truck cabs.

The engineering of the truck will fit their established model used in their cars: a chassis that mounts the batteries low, under the cab, and multiple electric motors at the rear.

For the Tesla semi, I’d expect that , they’ll work with a base chassis that’s closer to a conventional truck, but undersling several large battery packs low, as well as using the under-hood area for more battery storage. The motors would be two per rear axle, with options for both axles to be powered for four motors, or just one, for two motors.

The use of a more conventional truck chassis would be to be better able to meet the strict dimensional standards of trucks, and, ideally, to leverage an existing base of suspension, brake, trailer engagement equipment, and other common parts.

Weight would be an issue, as batteries are heavy; even with the removal of the diesel drivetrain and all related components, I suspect the mass of the batteries will prove to be heavier for the desired range.

Range, of course, is the big issue. According to the US Department of Transportation, . That’s a good target number for a Tesla semi, and is already in the ballpark of what their electric cars accomplish.

Hopefully, the greater volume of batteries will allow for a range of around 250 miles, though there’s so many variables involved that it’s hard to know exactly what would be enough. This is especially important since recharging the vast number of batteries needed for a semi will be dramatically more time consuming than just filling a truck up with diesel.

That issue, though, may have an interesting solution. Battery-swapping technology and stations have never really caught on, despite their huge advantage: nearly instant recharging.

The issues preventing battery swapping from catching on usually stems from the physical difficulty of removing the heavy battery packs. But what if Tesla builds not just semi truck prime movers—but also the trailers?

Tesla could build trailers (or offer a retrofit kit for trailers) that would mount a number of batteries right onto the underside of the trailer chassis. Doing so would accomplish two things: it could provide the necessary stored energy to dramatically increase range and offer a solution for a quick swap/recharge.

A truck could make one run that nearly depleted its batteries, and when it comes to drop off its load and pick up another, that new load could be on a trailer with a fully recharged battery pack. There’s already a physical swapping of components when a truck changes loads, so it may as well be used as a chance to swap in fresh batteries.

Of course, weight is still an issue here, and, frankly, I just don’t know enough about Tesla’s planned battery tech to know how big an issue the weight will be.

The fuel savings and pollution reduction to be gained by moving heavy-duty trucks away from diesel could be very considerable, if more electricity-generating plants that work from clean sources are built to accommodate the increased demand. It’s an exciting idea.

Also interesting is the use of autonomy or semi-autonomy for these trucks. In many ways, highway-based trucking is an ideal platform for autonomous driving, since so much of the driving is long stretches of relatively straight highway—the kind of driving Tesla’s system is best at, at least right now.

Truckers would still be required to handle the highly skilled and very tricky business of navigating a huge truck through urban traffic and environments, and getting trucks into and out of loading docks, which is, of course no joke. We’ve all seen this, right?

We probably have a way to go until an autonomous truck can pull something like that off with similar speed and grace.

This means that a truck driver’s job could become one where they’re only really needed for the high-skill bits at the beginning and end, and the long, tedious, boring middle part—the part where fatigue and distracting lot lizard fantasies are the most likely to cause accidents—can be left to the machines.

In some ways, truckers will become more like aircraft pilots, all on for takeoff and landing, but letting an autopilot handle most of the boring middle. At least until we hit a more full degree of autonomy, they’d still need to remain alert, but it’s possible to imagine a time when much of the highway driving can happen while the trucker sleeps or catches up on Game of Thrones or writes his or her screenplay about a sexy trucker who can travel through time.

A semi truck can be the best platform for their Autopilot system, and, because the driver of the truck is there doing a job, may than their cars have. I mean, that’s optimistic, but maybe. Also, trucks running autonomous systems would provide a wealth of data and experience that would then be uploaded back to Tesla to make future revisions better and safer.

I think the real challenges here will be balancing the battery load needed for the range they want and the overall vehicle weight, which is strictly regulated. A system that leverages trailers as battery packs could provide the solution to long charge times, too, becoming the first successful battery-swapping enterprise of any scale.

I’m very curious to see what these Tesla semi trucks turn out to be. And Elon, if you guys haven’t thought of the trailer-as-swappable-battery thing, give me a call. I’ll cut you a deal on the (nonexistent) rights to it.