For several decades, transportation professionals have advocated the “4 E’s” (more recently, they are “5 E’s”). Indeed, Boulder transportation staff, at countless meetings I attended, solemnly and triumphantly assured the Transportation Advisory Board I served on that they were implementing the “5 E’s.” All was well in terms of our improvement methodology, therefore, in transportation for Boulder, we were led to believe.
But the mantra implies that each of the “5 E’s” are equally important. This is absolutely untrue. It is a false equivalency. The “E” of engineering for safer, more attentive streets is, by far, the most important tactic for achieving Boulder transportation objectives. The other four (education, evaluation, enforcement, and encouragement) are helpful, but do not come close to the effectiveness of revising streets through engineering.
A much more accurate way of stating this concept is to state that there is one primary “E,” engineering, and four secondary “E’s.”