The emissions station is in your ZIP code. The repair shop is three miles away.
Derwood has the county’s central VEIP station. When a car fails it, the fix is a short run down Frederick Road to Karnon Automotive, and the safety inspection for a used-car sale is done here too.
Chieftain Avenue tests. Stonestreet Avenue fixes.
One of the county’s two full-service emissions stations (the MVA calls it the “Rockville” station, but it sits at 15910 Chieftain Ave, Derwood, off Redland Road about half a mile east of MD-355; the other is in Silver Spring, off US-29) tests cars, and only tests them. It opens early on Tuesdays and Wednesdays (7 AM to 7 PM), runs 8:30 to 5 on Monday, Thursday and Friday, and 7 to 1 on Saturday; the state station does not take appointments, so you wait in line there. Karnon Automotive does take them: call (301) 444-4410 to book, or walk in and wait your turn.
Failed the VEIP test?
A lit check-engine light or a monitor that has not completed is a shop problem, not a state one. The fault gets read and fixed here, the car is driven enough to set its readiness monitors, then it goes back to Chieftain Avenue for the retest.
Selling or buying a car?
That needs the other inspection: the Maryland Safety Inspection from a licensed station, valid for 90 days. Karnon Automotive is one, and if something fails it can be repaired and re-inspected without leaving the building.
Titling and paperwork
The nearest MVA branch that handles titling is Walnut Hill at 16520 S. Westland Dr in Gaithersburg, off MD-355 at Shady Grove Road, about two to three miles from central Derwood. The Gaithersburg branch at 15 Metropolitan Grove Rd, roughly six miles away, also has a self-service emissions kiosk. Inspection results reach the MVA electronically, so there is nothing to carry.
Frederick Road, then Hungerford Drive, then the tracks
MD-355 does the whole job: it is Frederick Road through Derwood, becomes Hungerford Drive as it enters Rockville, and passes the Rockville station a block from the shop. From the center of the Derwood CDP that is a bit under three miles. Call it ten minutes outside rush hour. The shop is on the east side of the rail line, on N Stonestreet Avenue.
Leaving the car for the day? Shady Grove station is Derwood’s Metro stop and the end of the Red Line; Rockville is one stop toward Glenmont. Ride On Route 59 also links Rockville station to Shady Grove by way of Stonestreet Avenue, Gude Drive and Crabbs Branch Way, seven days a week, and Ride On buses are currently fare-free.
Note for anyone who remembers the old B&O stop: Derwood has had no train station since its depot burned in 1954. The nearest MARC platforms are Rockville and the tiny Washington Grove flag stop, each about three miles away; Rockville has the full Brunswick Line schedule.
A small place with a big mailing area
The Derwood census-designated place is tiny, about 2,500 people on well under a square mile at the 2020 census, but since 1974 the whole 20855 ZIP code has carried the Derwood name, so “Derwood” in everyday use runs from the Shady Grove garages to the edge of Rock Creek Regional Park and Lake Needwood. It is an unincorporated area, north of Rockville and southeast of Gaithersburg, and it is a driving place: in recent Census estimates just over half of workers drive alone, about one in eight ride transit, and the typical household keeps two cars.
That commuter pattern is why the drop-off routine works from here: a quick hop down 355 in the morning, one Metro stop back to Shady Grove, and a call from us when it is ready.