Photo by PMC 1stPix on Flickr.

Whether we are prepared for it or not, the next revolution in transportation will be here soon, and it won’t be streetcars, monorails, segways, or electric vehicles. It will be self-driving cars, and the adoption of this technology will change everything we accept as a given in the field of transportation planning.

There is a fundamental flaw in the practice of transportation planning. Our local and regional transportation models assume that 20 years from now, the transportation system will be largely the same, with slight adjustments on the margin.

But history shows that every so often, unexpected technology arises. The most obvious was the move from horses and horse-conveyed vehicles for personal and short-haul transportation to the automobile, but it also happened with railroads superseding canals and short-distance shipping, and airplanes superseding railroads for long-distance personal travel.

In only 32 years at the turn of the twentieth century, the primary power source for human mobility for 7 millennia became obsolete. If there was a comparable transportation planning field at the time, using our current system of forecasting, their models from 1890 would have estimated a linear increase in horse trips for the next 30 years, with some additional subway and horse-drawn streetcar lines.

They would not have imagined that there would be no horses at all. Instead, they would need a complex set of signal and traffic control technologies to address the new safety and mobility issues presented by automobiles.

Today we are at a similar inflection point.  The occasional news story in Popular Science or the New York Times describes the wondrous technology that allows cars to operate under complex scenarios without any driver input.  However, we don’t hear a peep from transportation planning organizations about how society will adapt and plan for this change, even though it seems increasingly imminent.

Washingtonian recently interviewed Michael Pack, the region’s foremost traffic technologist. The interview is alarming: “I ask how long before we can all stop driving and let the cars do the work,” the interviewer asks. Pack responds, “Oh, a while, Maybe 30 years.” Pack appears to be considering a network of interconnected cars that can talk to each other and have a situational awareness that allows them to travel at 65 mph and 6 inches from one bumper to the next.

If Pack’s estimate is reliable, then that means we should start seeing the first generation of autonomous cars that replace the human driver with superior situational awareness in a matter of years. It also means we are already within the 30-year window where transportation planners should anticipate adoption of this technology and its consequences.

My best guess, based on publicly available information, is that within 7-12 years, there will be a commercially available autonomous vehicle sold in the US

In sharing this theory, I’ve heard my share of skepticism. But most people would accept on faith that within 100 years we’ll have autonomous vehicles. Some would accept that they’ll be here in 50 years, while few would accept that we’ll have them in 5 years. So at heart, the discussion is not a question of if this technology will develop, but when, and whether we have to start thinking about it from a policy and planning standpoint.

Whichever manufacturer is first to roll out a consumer-ready version of this technology will have a blockbuster product, so the economic incentive to be first is enormous.

In a future post, I’ll discuss some of the changes we’re likely to see in a world with self-driving cars.

Will Handsfield is the transportation director for the Georgetown Business Improvement District, and has worked on transportation projects in Los Angeles, Denver, and the metropolitan Washington region. Will bike commutes and lives with his wife and three children in the Lincoln Park neighborhood of Capitol Hill.