The stop sign, for all its utilitarian simplicity, has a severe and critical shortcoming: it has two different roles, both marked by the same sign (Figure 1).
The two situations, and what the driver must do in each case:
- All-way stop: driver can casually check for other cars right there at the intersection, and then proceed.
- Two-way stop: driver must look far down the road for quite some distance to identify any fast-traveling cross traffic.
These two situations are TOTALLY DIFFERENT, but the sign marking them is the same (Figure 1).
Fig. 1: Is this an all-way stop or a two-way stop? Who knows! See Figure 2 for the answer.
Fig 2: Oh, it was a two-way stop. I hope the driver looked far down the road before proceeding!
Previous attempts at solving this problem:
This is a recognized problem, and sign designers have attempted to (poorly) solve it before, as shown in Figure 3.
So far, they have been completely unsuccessful.
Fig 3: Some (but not all!) signs specifically indicate “Cross traffic does not stop” or “All-way stop.” But just the fact that a subtitle is required is an admission that these signs are fundamentally flawed.
The “all-way” and “partial-way” stop signs need to be clearly different at a glance.
See Figure 4 for a proposal that is backwards-compatible with existing stop signs.
Fig 4: Proposal A (“Four leafed clover”): The traditional “octagon” stop sign (left) will now indicate partial-way stops: its meaning is now upgraded to “be EXTRA CAREFUL, because the cross traffic does not stop!”
The new “four leafed clover” stop sign (right) indicates an all-way stop, where the driver only needs to look for traffic at that stop sign before proceeding. Because existing stop signs are all the “be extra careful!” kind, we don’t need to worry about immediately replacing all existing stop signs.
Fig 5: Here is an alternative form of the “four leaf clover” sign proposed above.
Fig 6: Substantially altering the silhouette of the stop sign would make the difference even more obvious, as shown in this “emphatically on-fire” stop sign.
Fig 7: Sometimes it may be insufficient to just indicate whether or not an intersection is all-way or partial-way. For example, in a (rare) partial-way intersection with more than four intersecting streets, a driver may entirely miss a street.
Here, the number of dots on the stop sign indicates the number of non-stopping incoming roads. This allows the driver to know how many roads they should be looking out for.
So the five-dot sign would indicate a (very rare) 6-way intersection with only one stop sign, the three-dot one would be a four-way intersection (again, with just one stop sign), and the no-dot sign would indicate an all-way stop.
(A reflective yellow border would indicate that this is a “new style” stop sign, to avoid confusion with the previous no-border signs—otherwise, every old-style stop sign would seem to indicate an all-way stop.)
Bonus idea: It has been shown that humans have a deep-seated primal reaction to certain stimuli, such as a silhouette of a spider or of a snake about to strike. In order to make the stop sign stand out even more, so no one would ever miss it out of the corner of their eye, perhaps it could be fashioned into the likeness of a cobra, poised to strike.
PROS: May reduce traffic accidents, especially if a simple backwards-compatible system like the one in Figure 4 is adopted.
CONS: People might start to treat the partial-way “four leaf clover” stop signs like “yield” signs, and roll right through them.