General Provisions
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10. Bicycle – a vehicle equipped with two wheels, propelled exclusively by muscular force using pedals or cranks.
25. Bicycle lane – a subdivision of the roadway, sidewalk, or shoulder, or a separate lane, specially designed, marked, and signposted for the exclusive use of bicycles and mopeds.
Article 12 (1) To circulate on public roads, vehicles, except those pushed or pulled by hand and bicycles, must be registered or licensed, as appropriate, and display registration plates with forms, dimensions, and content according to current standards.

Article 14 – Requirements for bicycles on public roads:
a) must have an effective braking device;
b) must have a suitable and functional steering system;
c) must be equipped with an audible warning system; the use of vehicle-specific horns is prohibited;
d) must have a white or yellow front light, a red rear light, and at least one visible red fluorescent-reflective device;
e) must have elements or devices that, when in motion, form a continuous fluorescent-reflective orange circle on the wheel spokes.

Article 15 – Bicycle trailers:
A trailer attached to a bicycle must have a red fluorescent-reflective device at the rear, and if the bicycle’s rear light is obscured by the trailer, the trailer must also have a red light.

Article 41 (3)
If a road has a dedicated bicycle lane, bicycles and mopeds must be driven only on that lane.

Use of the Roadway
Article 100 – Vehicles must be driven only on roads, lanes, or paths designated for their category. If there are no dedicated lanes for mopeds, bicycles, or other non-motorized vehicles, they may also use the shoulder in the direction of travel if it can be done safely.
Article 142 – Voluntary stopping of vehicles is prohibited: k) on lanes mandatory for pedestrians and/or cyclists or lanes reserved for certain vehicle categories, as signposted.

Rules for Other Road Users
1. Circulation of bicycles and mopeds Article 160
(1) Bicycles and mopeds must be ridden in a single file on public roads.
(2) Persons without a driving license may ride mopeds on public roads only if they can prove completion of a traffic legislation course at an authorized training unit.
(3) If there is a marked bicycle lane in the direction of travel, riders must use that lane. Other traffic participants are prohibited from riding on the bicycle lane.
(4) Cyclists are recommended to wear an approved helmet when riding on public roads.

Article 161 – Cycling and moped rules
(1) Bicycle and moped riders are prohibited from:
a) riding on road sections marked with the "No Access for Bicycles" sign;
b) learning to ride bicycles or mopeds on heavily trafficked roads;
c) riding on sidewalks, except where designated lanes exist;
d) riding without at least one hand on the handlebar and both feet on the pedals;
e) riding side by side, except during organized sports competitions;
f) riding under the influence of alcohol, drugs, or medications with similar effects;
g) holding onto or being towed by another vehicle;
h) carrying another person, except for a child under 7 years if the bicycle is equipped with a special front seat, or if the bicycle is designed to carry additional passengers;
i) riding on the roadway if a side path, lane, or shoulder is available;
j) carrying or towing objects that may obstruct safe riding or endanger others;
k) riding on park paths unless pedestrian traffic is not obstructed;
l) riding at night or in low visibility without meeting the requirements of Articles 14 and 16;
m) riding on icy, snowy, or slippery roads;
n) riding with brake system defects or without a warning device;
o) crossing pedestrian crossings while riding a bicycle or moped;
p) riding in lanes other than the curb lane or shoulder, except when positioning for a left turn before an intersection;
r) riding without fluorescent-reflective clothing from dusk to dawn or when visibility is poor;
s) riding without maintaining wheel contact with the ground.

(2) While riding on public roads, bicycle riders must carry an identity document, and moped riders must also carry proof of traffic legislation course completion and vehicle registration certificate.

This excerpt comes from the Regulation implementing the Emergency Government Ordinance no. 195/2002 regarding public road traffic, dated 04.10.2006.