Neither is better than the other generally, except that putting directional-bearing alt names on one-way roads seems absurd, and may conceivably even cause problems in places where, say, some streets are addressed à la "2201 Highway 13 West"—not 'westbound', but 'west of some central road'...
The question of which is better, if
we take it as a given that we always want BDP to be active, depends entirely on the circumstances. If a highway becomes divided through a town, and re-undivides on the other side of town, then it is easier to add the no-cardinal alt name to both—though, unless it's a one-way pair in town, the highway will usually have some local name that doesn't have directionals on it anyway. On the other hand, where a divided highway becomes undivided through a town (e.g., ditches the median for a center shared turn lane), it would be simpler to add the directional names as alt names on the undivided part—though again, probably not necessary, assuming that there is a local name through town anyway that does not have directionals on it.
I think, in many cases, it is moot, and to be honest this is overkill as a general rule. Again, "really, this is not necessary on divided roadways unless some U turn somewhere requires more than one segment to carry out. In other words, typically it's a freeway problem."
The countervailing motives here are (1) "don't allow BDP to overreact to the desire to turn around" and (2) "allow BDP to function". Generally, both are freeway/expressway problems, and most if not all freeways/expressways should be divided anyway.
Starting with (1),
The guidance that "all alternate names" must include cardinal directions where primary names do may be unnecessarily broad, then, as a U turn on an uncontrolled-access divided roadway is typically made in the median, over a single segment. This is not prevented by BDP.
Really, the guidance is only necessary where turning around would require more than one segment off the highway—typically, a handful of ramps and one or two segments of the other served by the interchange. This only really happens on limited- or controlled-access highways, although there are exceptions. But the exceptions can lead to a different problem.
One exception might be found here
. Easily the best way to effect a U turn on Clearview is to take advantage of the cloverleaf interchange. Continuing either north or south to the next opportunity may require waiting through at least two traffic lights, some of which have very long wait times during the rush. But "Clearview Pkwy" doesn't have any cardinals, so Waze won't give this route. What is the solution here? Add arbitrary cardinals for a road that isn't even a numbered highway?
Not as a general rule, I don't think. Take this section of nearby N Causeway Blvd
, which technically qualifies as an expressway. I suppose there are worse things than adding N and S to the end of the name, but "N Causeway Blvd N" and "N Causeway Blvd S" seems like we are adding some confusing elements for no purpose (because the interchange design means it can't be used for U turns anyway).
Maybe the better solution is to add a 'routing alt name' to all the necessary segments in that interchange so it isn't considered a detour. Not sure if that would work.
On to (2),
While it is admirable to want BDP to function, is it really necessary in all
cases? In the Clearview example above, say for purpose of argument we added the cardinals to Clearview just for that interchange, to allow U turns. Any traffic situation that takes you off Clearview and puts you back on it within 5 km would have to take you pretty far out of the way to another Interstate crossing. The situation on Clearview must be pretty bad to make it worth it to go that far out of the way for something faster. In this situation, is it really important that the other route be so
much quicker as to override the BDP penalty? Or is it not enough that the other route is marginally
quicker and exceptionally less frustrating?
That is one example, and it won't be the same everywhere, granted. But there are plenty other examples like Clearview where BDP is really unnecessary, and not always for the same reason. Consider the rural state highway that becomes divided for a quarter-mile stretch through a freeway interchange. Assume for purposes of discussion that it is desirable to divide this stretch on the Waze map (it often is). What do we lose by adding directions to the divided part? BDP with a 500 m threshold. In most such situations there is no other way to get across that freeway for at least a mile, often several miles, in either direction, so there is no feasible scenario in which that BDP does anything anyway.
BDP is designed primarily to prevent off-and-on-again routing on freeways. The other benefits, if they are benefits, are ancillary at best, and I for one would expect and hope to be taken off a Major Highway to be routed down a nearby Street if it would save me a minute or two.
So, in short,
I am not sure such a rule is strictly necessary except on freeways and expressways where there is a genuine problem with using directionless alt names (and no real reason to do so anyway, as freeways and expressways by definition shouldn't have addresses on them). Otherwise, other places where it might be beneficial to neuter BDP (e.g., Clearview Pkwy, supra) should be handled case-by-case.