Clinched Highway Mapping

froggie · Posted: Sun Jan 30, 2011 3:33 pm Post subject: Maryland: Various routes

Some notes/suggestions from a trip this morning:

MD 117: Though SHA docs show it ending at Fulks Corner Rd, there's END signage one block further east at Summit Ave.

MD 121: Not sure what, if anything, you want to do with this one. Officially (i.e. per SHA maps and the HLR), MD 121 ends on the north end of the interchange with I-270, and it's MD 121A that follows the original routing north of I-270, with no state route connection between the two (i.e. gapped). Aside from JUNCTION signage and a southbound reassurance shield, this northern segment is signed as "TO" MD 121.

The way I see it, you have three options: A) end MD 121 at I-270; B) end the current list at I-270 and create a new "121A" or "121_N" list to account for the gap; or C) leave it as-is. I don't really have a preference...just wanted to bring up this situation.

MD 189: suggest points at Democracy Blvd and Montrose Rd, as both are major roads that connect to I-270. Montrose Rd in particular is becoming a major arterial across southern Montgomery County.
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Froggie
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dcons · Posted: Sun Feb 06, 2011 10:39 pm Post subject: MD 121 northern segment

Interestingly, there is a "MD 121 NORTH" sign on the dead-end portion of the northern segment, about 100 yards before the intersection with Gateway Center Dr. I took a picture of the sign on Saturday, which I can send if you want.

There is also an "END MD 121" sign at the junction with MD 355, as well as signage along MD 355 indicating that Clarksburg Rd is MD 121.

I would go with your Option B: end the current MD 121 file at I-270, and create a new file for the northern segment (MD 121A). The MD 121A segment would have three points: the cul-de-sac, Gateway Center Dr, and MD 355.

Dave

froggie · Posted: Sat Feb 12, 2011 8:23 pm Post subject: MD 564

Another one: MD 564. As it currently exists, this list is in error. Signage on MD 197 clearly notes "TO MD 564". And the HLR has it not connecting to MD 197, but instead continuing southeast on what OSM calls "Normal School Rd" (the other map entities call it "Laurel Bowie Rd") to where it dead ends near the WB&A crossing of MD 197.

Two ways you could do this: A) end it where 11th St peels off to connect to MD 197; B) create a point where 11th St peels off, and put a terminus point ("End"?) at the dead-end.
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Froggie
http://www.ajfroggie.com

admin · Posted: Tue Feb 15, 2011 11:26 pm Post subject:

Extended MD 117 and relocated MD 564 in the next update.

Looking at signs in GMSV for MD 121, the only possible gap is the 0.1 miles of Gateway Center Drive. The gap is the result of a rather minor relocation of the intersection with Stringtown Road and a maintenance change. MD 121 NB is signed without "TO" at both the I-270 NB off-ramp and at the turn from GateWay Center Dr. NB to Clarksburg Rd. NB. So the continuity seems implied to me, and I think the best choice is to leave it as one piece.