There were several map problems that kept auto-generating over & over again, and nothing I did would eliminate them from coming up. The five point intersections at Blair Mill Rd/New Rd and Sycamore Ave/Mill Rd were generating "road missing" map problems. This was especially true with Mill Rd. Due to the extreme angle that New Rd & Mill Rd both approach these intersections, both roads had to be disconnected from the intersections and junctioned separately. This would cause URs from people who would get something like 'stay right then turn left' or wouldn't get their turn prompt at the correct location. It was a vicious cycle. If you take a look at how Mill Rd now intersects with Easton Rd, you can see how that issue has been resolved by splitting the road. The bonus here is that I was able to restrict U-Turns from 611 N to 611 S at this intersection. Same thing at Blair Mill Rd, where U-Turns from N to S are prohibited.

There are a number of intersections that allow u-turns as a legitimate traffic movement, and having a single road didn't allow for them to occur:

NB & SB at Fitzwatertown Rd, NB @ Maryland Rd
SB @ Mill Rd/Sycamore Ave
SB @ Blair Mill/New Rd.

There were a number of intersections with restricted turns where Waze would still inexplicably try to route people through them. I witnessed this several times myself. By splitting the road, it created additional turn restrictions (or made it impossible to turn) at some of these intersections which seem to be enough to make Waze realize it's a bad idea. Same thing for people using Andrea Dr or Knock & Knoll Circle. Left turns out of these roads are blocked by the median, yet Waze would still want people to make left turns onto 611. Now, these people have the routing option to turn right onto 611 and make a U-Turn at Fitzwatertown Rd (where it is legal) in order to go 611 N.

HavanaDay wrote:I was trying to figure something out without changing the roads. Here is what I came up with. Playing a little devils advocate with this one. And you said that the u-turn restrictions were a bonus so lets forget about that for a second. In the drawing below why doesn't that give correct turn instructions.

Link

gettingthere wrote:If you are following the recent Parking Lot thread, yep - you can't trust the restrictions from a stub road, Parking Lot with Parking Lot road types in the mix, or many cul-de sac's, etc.

gettingthere wrote:Of course the 'take a left turn' instruction vs. a real 'make a U-Turn' instruction at bowtie intersections that allow the 'U-Turn' is not clear to Wazers that are navigating.

gettingthere wrote:In fact, how would you propose that this would actually work? Basically the separating line would create two independent roads but the visual would show as one road with the line down the middle.

How would we deal with Wazers who start on one side of the other side (in a parking lot) of the road with a separating line configured? In many of these roads where we would want to use this function there are cut throughs in the median for turns - but no way to map them if we have a single road with a separating line.

jasonh300 wrote:New parts in green.
Stuff to remove in red.

Some formal guidelines - A road should be split if:

• There is at least 5 meters of non-drivable surface between directions of travel. (This means a median of some type like cement, planter boxes, trees, or just grass.
• There is a non-drivable surface (physical barrier) between directions of travel that prohibit cross traffic or left turns, necessitating U-turns at designated intersections. (This should be done selectively - only as a last resort when there are Update Requests that cannot be solved otherwise.)
• GPS tracks show a clearly definable gap/blank area between the color-by-azimuth arrows at the 100m zoom level.
• It is an Interstate Highway (USA) or other Limited Access Highway using the "Freeway" road type.

A road should not be split because:

• There is a curb or non-drivable media less than 5m wide between lanes of travel with the exception of roads where U-Turns are required because some left turns or crossings are prevented by the barrier.
• There is a drivable turn lane, even a wide one, between directions of travel, but no physical barrier (often called a suicide lane, reversible lane, tidal flow).
• There are a lot of roads intersecting which can only turn onto the nearest direction of travel.
• Google Maps or other mapping source show it as a split road

(I strongly believe that, for every mile of road that an AM wants to split into one-way roads, he should first merge a mile of split roads back into a two-way road. Check out what's involved. It builds character.)