This involves the area between nodes 98632564 and 2050306206, in Chiefland FL. Florida DOT decided that there were too many accidents involving traffic attempting to cross the busy N-S highway, so they made a physical change to the intersection.

The change involves installing physical lane restrictions (curb height) so that south-bound traffic can turn left (towards east) and north-bound traffic can turn left (towards west), but cross traffic (on way 11059266) cannot pass thru the intersection. Traffic from that way, attempting to enter the intersection, can now only turn right. As far as I can see, there is no restriction (either physical or by signage) for north-bound or south-bound traffic from making a U-turn.

Is this merely splitting way 11059266 into two segments, or do the turn restrictions/barriers need to be shown ? Existing satellite images do not yet reveal the new lane configuration.

asked 09 May, 12:35

NitaRae's gravatar image

accept rate: 0%

edited 09 May, 16:55

TZorn's gravatar image


So if I understood you correctly the only restrictions are for traffic coming from the NW 21st Ave may not go straight on (in either direction).

You need to add two turn restrictions:

  1. Split the three ways at the two nodes. You will get seven ways after that.
  2. Use the turn restrictions plugin (you may need to install it in JOSM) to add the first restriction: add the section of 21 Ave west of the intersection as 'from' add the southern part of the southbound Young Boulevard as 'to', add the western crossing node as via, chose the type 'only_right_turn'
  3. Do the same for 21 Ave coming from the east.

Have a look at the turn restrictions wiki page for reference.

permanent link

answered 09 May, 16:48

TZorn's gravatar image

accept rate: 11%

edited 09 May, 16:52

NW 21st Ave may only turn right. That traffic may not go straight or turn left. Both of those maneuvers is what led to many of the accidents. Traffic on NW Young Blvd may either turn left (including presumably a U-turn), go straight (using either of the main lanes), or turn right. Two new left turn lanes were created, with curb-height barriers between them, to accomplish this, and to prevent traffic exiting NW 21st Ave from attempting a straight or left.

(09 May, 17:25) NitaRae

Yes, I phrased that incorrectly in my assumption. But what I suggested already covers that NW21 may only turn right.

Additionally to the turn restrictions (which control the routing) you could also map the lanes on the incoming road sections as described in the wiki.

You could also map the curbs by splitting the ways but then it gets complex and in my eyes doesn't justify the ends.

(09 May, 17:43) TZorn

I'm getting some error messages from the validator concerning splitting the two N-S ways. It thinks that there is a 'north' relationship and a 'south' relationship that may be broken (or missing). Is this a validator bug, or is there something extra I have to do after splitting them ?

(09 May, 22:26) NitaRae

Note that the iD editor has an interface for turn restrictions.

In this case, selecting the node for the restriction will show a turn restriction view of the intersection in the left panel.

Selecting one the incoming ways will do the relevant way-splitting and clicking once or twice on the arrow on the destination way will mark that (to) way as 'prohibited' or 'mandatory' respectively. Any other incoming ways with restrictions can be selected by clicking on them (away from the arrow) and repeating the process.

An animation of this editor is shown on the previously mentioned wiki page.

I don't know if iD will correcty preserve the route relations, but it is suggesting that just splitting the ways introduces 12 edits, so I suspect it is attempting to preserve something.

(09 May, 22:55) InsertUser

Whatever I am running into here, it has nothing (specifically) to do with the turn restriction. I can split way 194529137 at node 2050306206, attempt an upload, and the warning about north/south pops up. Both of those ways participate in 4 relationships, and each has a long list of members. Some of the members have no role, some have 'forward', and some have 'north' or 'south'. I don't know enough about roles to see what the precise problem is, but I suspect that splitting the way is causing something to be put out of order in the list of members. I'm using JOSM, so perhaps iD doesn't have this specific problem. Any thoughts ?

(10 May, 00:59) NitaRae

I have tested it now. The validation issues have nothing to do with splitting the ways. They already exist when you run the validator before splitting. Non-standard or no roles have been used in these relations. They should be fixed at some point in time by someone but you don't have to take care of that now.

Just go ahead uploading the splits. To be on the save side and make sure JOSM treats the relations correctly you can download the missing members before splitting: select one of the N-S ways, select the four relations in the "member of" section, right click, download members.

Then just ignore the warning when uploading.

(10 May, 06:23) TZorn

When I try to do the entire sequence: splitting NW 21st, splitting both N-S truck roads, adding the relationships for 'only right turn', making sure that the members of the relationships are tagged 'from', 'via' and 'to', I end up with 5 errors and 5 warnings. I could proceed, but the errors leave me with pause if this is so much fluff, or if something is truly broken.

(10 May, 15:05) NitaRae

Upon careful examination, I found that the turnrestriction plugin had created two restrictions for every attempt to create one. The second one had no members, so I deleted it/them, and now I only received warnings, so the changes have been implemented.

(10 May, 15:28) NitaRae
showing 5 of 8 show 3 more comments
Your answer
toggle preview

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here



Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text]( "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:


question asked: 09 May, 12:35

question was seen: 108 times

last updated: 10 May, 15:28

powered by OSQA