The Man Who Invented Intelligent Traffic Control a Century Too Early
With traffic accidents soaring, Charles Adler imagined an intelligent transportation system that was ahead of its time
On a cool December day in 1925, Charles Adler Jr. stood beside Falls Road, a state highway on Baltimore’s north side. He was there to test his latest invention: an electromagnetic apparatus that would automatically slow cars traveling at unsafe speeds. Adler had embedded magnetic plates in the road where it led into a precarious curve, and he was now waiting for a specially prepared car to drive over the magnets. The magnets would activate a speed governor connected to the vehicle’s engine, slowing it to 24 kilometers per hour.
Adler had developed this automatic speed-control system for railroad crossings, the scene of many deadly accidents at the time. But he soon came to imagine all sorts of applications for it: “Dangerous road intersections, streets on which schools are located, bad curves, and even steep down grades,” according to an article in the Baltimore News.
On that December day, the test vehicle drove down Falls Road as Adler and his supporters looked on. The magnets tripped the governor, cutting the car’s speed; the demonstration went off without a hitch. Adler spent the next year promoting his invention and attracting investors. He had good reason to be hopeful: With traffic accidents soaring throughout the United States, communities were clamoring for solutions. Several years earlier, a road signal he’d designed for train crossings had been readily adopted by 40 railroad companies nationwide.
After little more than a year, however, Adler’s efforts had led nowhere. Over the next decade he continued to refine his designs and devise new ones, but his many inventions to make roads safer never saw widespread adoption.
Today, Adler’s automatic speed-control system looks like an early version of a smart road or an intelligent transportation system. These sensing and communications systems inform drivers, or fully autonomous cars, of conditions on the road ahead, thereby boosting both safety and efficiency. Such a system might automatically drop a car’s speed as it approaches stalled traffic, an accident, or a dangerous intersection, much as Adler sought to do. Indeed, he looks like a man before his time. Understanding just why Adler failed can tell us much about the nature of innovation and the acceptance of new ideas.