# Transportation (GTR)

## Title 21. Vehicle Laws -- Rules of the Road

### Subtitle 14. Operation of Vehicles on Certain Toll Facilities

#### Section 21-1412

(a) Except at the direction of authorized personnel, vehicular traffic may not cross the double white lines that designate the vehicular traffic lanes in a tunnel.

(b) Except at the direction of authorized personnel, trucks and slow moving vehicles may be driven only in the right lane of a tunnel.

(c) The driver of a vehicle may not sound his horn or flash his headlights in a tunnel.

(d) While in a tunnel, a person may not use any cutout or other device that allows exhaust gases to escape a motor without passing through a muffler or silencer.

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Md. Code Ann., Transp. (as displayed at mgaleg.maryland.gov, October 16, 2026)