Clinched Highway Mapping

Bickendan · Joined: 29 Jul 2008 Posts: 1018 Location: Portland, OR

Exit 27 has been relocated to a new interchange about half-mile south. The new interchange officially opened on the 16th, and the old one closed the 17th.

Exit 71 is being repositioned. It somehow got a quarter mile west from the highway...
Exit 76A is being renamed to 76_N.
Exit 189A -> 189_N.

In Portland, four missing interchanges (295_N Taylors Ferry Rd, 296B Multnomah Blvd [296A, Barbur Blvd/Spring Garden Ave, has been slightly repositioned and relabeled from 296], 302C Greeley Ave, 306_N Denver Ave) have been added, and two have been repositioned (299A and B) to better reflect the tangle of ramps and overlapping exits along I-405 in the Ross Island Interchange.
Of note, 302C will appear before 302B in the file, as 302B is at the center of the north I-5/405 stack, while 302C exits just before the stack's center point. 306_N is a southbound only exit (northbound onramp) for Denver Ave, just north of 306B (Delta Park).

Shape points are being added to the file, as there is a difference of 5 miles between the actual highway (308) and what the on-site stats report (303).

yakra · Joined: 30 Jul 2008 Posts: 2600 Location: Area Code 207

Bickendan · Joined: 29 Jul 2008 Posts: 1018 Location: Portland, OR

I'd agree with you and revert the x_N tags to xA's, but that'd foul up exit 306
306A
306B
306_N (southbound side) Confused

Revert the others, leave 306 as the exception?

As for exit 302C... um... I'd have to clean up a number of CA's SR freeway files because I was very thorough. Technically, 302C does fit in the 302B footprint, but that would imply then that US 30 has access to the ramps when it doesn't.

admin · Posted: Sat Jul 25, 2009 2:17 am Post subject:

Like Eric says, use the A suffix style. No need to change 76A etc. There are no "_N"'s etc. in the exit number labels.

For 306, just keep 306A and 306B, then add 306 for Denver Ave. Or move 306B to account for that whole interchange instead of two half interchanges.

302B & C should have the same point 302B.

In general, don't get carried away with lots of points for lots of tangled ramps. A single point for the whole 302B/C tangle is much simpler and still effective.