I use this exit occasionally when I'm trying to get from 15 north / 340 east to MD-351 south at high traffic hours. The left turn off Exit 11 has only a stop sign, so lefts in the late afternoon are basically impossible; taking exit 9 and going through the subdivision to turn right on MD-180 (which turns into 351) takes far less time.
What I do wonder is if Maryland is ever going to figure out what they're doing with numbering the Mt Zion Rd exit. If tMDDOT wanted to use mileage-based exits based on US 15 mileage they screwed up already, as Exit 9 is at milepost 10.1 and exit 10 at milepost 11.1 ... or are these exit numbers really an attempt to be sequential with respect to US-340, in which case continuing the numbering onto 15 north makes no sense.
