Synopsis:
Requiring that a driver of a motor vehicle, when overtaking a bicycle, an Electric Personal Assistive Mobility Device (EPAMD), or a motor scooter, not pass unless the driver can do so safely without endangering the rider; requiring a driver of a motor vehicle to yield the right-of-way to a person who is riding a bicycle, an EPAMD, or a motor scooter in a bicycle lane; etc.
Full text of the bill: https://mlis.state.md.us/2008RS/bills/hb/hb0143f.pdf
Summary, status and hearing dates: https://mlis.state.md.us/2008rs/billfile/HB0143.htmoldId.20080123152825335

What’s a "play vehicle?"
Basically a play vehicle is supposed to be kids bikes.
(m) Play vehicle.- "Play vehicle" means a vehicle that:
(1) Has two or three wheels;
(2) Is propelled only by human power; and
(3) Is not a bicycle, as defined in Title 11 of this article.
"Bicycle" means a vehicle that:
(1) Is designed to be operated by human power;
(2) Has two or three wheels, of which one is more than 14 inches in diameter;
(3) Has a rear drive; and
(4) Has a wheel configuration as follows:
(i) If the vehicle has two wheels, with both wheels in tandem; or
(ii) If the vehicle has three wheels, with one front wheel and with two rear wheels that are spaced equidistant from the center of the vehicle.