Please note that the decrees mentioned here relate to Czech laws and regulations.
Extract from decree No. 341/2014 Coll. concerning hazard warning lights.
Decree on the approval of technical competence and technical conditions for the operation of vehicles on the road.
(E) Technical requirements for the fitting of vehicles with special warning lights and sound devices
1. One or more special warning lights emitting orange-colored light of an approved type or design shall, in addition to the prescribed external lighting devices, be equipped with:
(a) motor vehicles and trailers carrying out driving or roadside or stationary work,
b) motor vehicles and trailers, which by their dimensions or weight exceed the level specified in sections § 37 to 39, if stipulated by the ministry approving the technical competence of the vehicle type or the municipal authority of the municipality with extended competence
c) motor vehicles and trailers with their load exceeding the limit values set out in sections § 37 to 39, if determined by the authority that issued the permit for special use of the road pursuant to another legal regulation, 2)
(d) motor vehicles and trailers for which the ministry of approval of the vehicle type or the municipal authority of the municipality with extended competence so provides in the case of approval of the technical suitability of a conversion or an individual vehicle; or
(e) self-propelled and towed machinery of a width exceeding 3,00 m or for which the ministry approving the technical capability of a vehicle type or the municipal authority of a municipality with extended competence in the case of approval of the technical capability of an individual vehicle.
2. Tractors may be fitted with a special orange warning light, but which may be activated only if one of the cases referred to in paragraph 1 (a) occurs. a) to e).
3. The engagement of the special blue or orange warning light and the operation of the additional intermittent blue or orange warning light shall be independent of the other external vehicle lighting devices and shall be equipped with a yellow tell-tale tell-tale other than orange lights. colors mounted on the vehicle body using a magnet or vacuum suction cup without a separate switch.
4. The color of the special blue or orange warning light shall indicate the special nature of the vehicles and their position vis-à-vis all road users.
5. The special warning light device shall, as far as possible, be located at the highest point of the bodywork or superstructure or as close as possible to the highest point, approximately in the longitudinal median plane of the vehicle or approximately symmetrically on either side of that plane. In the case of a special blue warning light mounted on the vehicle body by means of a magnet or vacuum suction cup, it shall be permitted to be fitted on one side of the vehicle.
6. Special warning lights shall be located on the vehicle in such a way that at least one of them is directly visible from any point on a horizontal plane 1 m above the ground, 20 m from that light source.
7. Special blue warning light warning devices may be fitted on the vehicle with at most one pair of additional special warning lamps emitting an intermittent blue light flux of an approved type in front illuminated and symmetrical to the longitudinal vertical plane which are located at their lowest point of the illuminating surface. below 400 mm and, with its highest point, the illuminating surface not higher than 1500 mm above the ground. A special warning light device emitting blue light shall always be accompanied by a special audible warning device giving a sound signal with a continuously varying pitch - the siren. The frequency of pitch variations may be variable. In addition, the vehicles may be equipped with one pair of optional special rear flashing blue flashing warning lamps and a third optional special forward flashing blue flashing lamp located behind the vehicle windscreen.
8. Orange warning light special warning devices may be completed with a maximum of five pieces of additional special warning lights emitting an intermittent orange-colored light beam of the approved type at the front and five pieces at the rear symmetrical to the longitudinal vertical plane. They shall, with their lowest point, operate illuminating surfaces not less than 400 mm above the ground. The lights shall be arranged horizontally on the vehicle in such a row that the upper edge of the illuminating surface of the lamps can extend beyond the upper edge of the vehicle by a maximum of its height. They may be replaced by 13 pieces of additional special warning lights of an approved type emitting an intermittent orange light at the front and 13 pieces at the rear, symmetrical to the longitudinal vertical plane. Lights shall be located at their lowest point on the illuminating surface not less than 400 mm above the ground. The arrangement of lights may be in a square with a lateral edge and a lower edge of not more than four lights. The square shall be located on the vehicle in such a way that the upper edge of the illuminating surface of the upper lights shall not exceed the upper gauge of the vehicle. If the lights are also used on a trailer, the number may be up to 24. A special warning light emitting an orange-colored light shall not be supplemented by a special audible warning device.
9. Special warning lights shall comply with and be approved according to EHK No 65. Additional warning lights shall be approved. Vehicles that may be equipped with a special audible device supplemented by a special blue warning light device shall be laid down by another legal regulation.10)
10. Only approved special audible warning devices may be used for mounting on the vehicle. It shall be placed on the vehicle in such a way that it does not damage it or change its sound characteristics under any conditions. The sound level of these devices shall be at least 105 dB (A).
11. Vehicles equipped with a special warning audible device supplemented by a special blue warning device may furthermore be fitted with a retro-reflective outline or line marking approved in accordance with EHK regulation No. 104 for the visibility of such vehicles in view of the specific nature of their use in road traffic.
Extract from the decree 361/2000Coll. relating to the movement of vehicles with priority rights
Driving vehicles with the right of priority
(1) A driver of a vehicle who uses a special blue or blue and red warning light when performing tasks related to the performance of special duties, 2) possibly supplemented by a special audible warning signal (hereinafter referred to as "priority driving vehicle") is not obliged to observe § 4 písm. c), § 5 odst. 1 písm. f), g), h) a odst. 2 písm. f) a g),§ 6 odst. 5 a 6, § 7 odst. 1 písm. b), § 11, § 12 odst. 1, 2, 4, 5 a 6, § 13 až 17, § 18 odst. 2, 3, 4 a 8, § 19 odst. 2 a 3, § 20, § 21 odst. 2, 3 a 4, § 22, 23, § 24 odst. 3 a 4, § 25 odst. 1, 2, 3, 4, 5, § 26 odst. 3, § 27, § 28 odst. 2, 3 a 5, § 31, § 32 odst. 6, § 35, § 36 odst. 1 a 2 a § 39 odst. 4 a 5; however, it is obliged to take the necessary precautions not to jeopardize road safety.
(2) Special audible warning devices supplemented by a special blue warning light 2) may be fitted to vehicles
a) Ministries of the Interior used by the police and designated according to a special legal regulation, 13)
b) Prison services,
c) military police designated according to a special legal regulation, 12)
d) municipal police, 5) which designate the municipality,
e) used by the Fire Rescue Service of the Czech Republic or by fire protection units that are not part of the Fire Rescue Service of the Czech Republic,
f) mining rescue services;
g) failure of gas facilities,
h) ambulance service providers, medical transport service providers and emergency patient transport services;
i) the armed forces used by the military rescue services to carry out humanitarian humanitarian tasks.
j) customs administration designated according to a special legal regulation14),
k) General Inspection of Security Forces designated in accordance with a special legal regulation 45),
l) intelligence services in the carriage of classified information media or persons to whom they are protected.
(3) The Government may prescribe additional vehicles which may be equipped with a special audible warning device supplemented with a special blue warning light for the performance of tasks related to the performance of special duties.
(4) The driver of a vehicle with the right of priority ride may be a person older than 21 years, who must meet the conditions set by this Act.
(5) The driver of a vehicle with the right of priority driving must not eat, drink or smoke while driving.
(6) Paragraphs 1 and 4 shall apply mutatis mutandis to drivers of vehicles accompanied in the front and, in the case of more than three vehicles, also to the rear by vehicles of the armed forces or armed corps with priority right of way. Accompanying vehicles must have the side and dipped beam lights on.
(7) Drivers of other vehicles must allow vehicles with right of way and their accompanying vehicles to pass through safely and smoothly and, if necessary, stop vehicles in such a way that they do not interfere with them. Drivers of other vehicles shall not be included in the group consisting of vehicles with priority right and their accompanying vehicles.
(8) If a motorway or road for motor vehicles with at least two lanes is not freely passable due to a column of standing or slow moving vehicles, vehicle drivers are obliged to create a space for passing vehicles with right of priority between lanes; in doing so, they may enter the verge or the central dividing belt. If there are more than two lanes in one driving direction, this space shall be created between the leftmost traffic lane and the adjacent traffic lane. Only priority road vehicles, vehicles of the infrastructure manager and vehicles used for the elimination of the consequences of an accident or an obstacle to road traffic may enter this area.
(9) If the special warning light of blue or blue and red color is on when the vehicle is stationary, the drivers of other vehicles must reduce their speed and, if necessary, stop the vehicle.
(10) It is forbidden to use or to imitate the special warning lights and the special audible warning signal used by the vehicle with the right of priority driving in traffic on the road.
(11) Vehicles of the ministry of the interior used by the police and marked in accordance with a special legal regulation 13), vehicles used by the Fire Rescue Service of the Czech Republic or units of fire protection and vehicles of the emergency services provider may be equipped with a special blue and red warning light.
(1) A driver of a vehicle equipped with a special orange warning light may use this light only if his driving or working activities could endanger the safety of road traffic. If the work of this vehicle so requires, its driver shall not be required to comply with the provisions of the road traffic rules referred to in § 4 písm. c), § 7 odst. 1 písm. b), § 11 odst. 2, § 12 odst. 1, 2 a 4, § 13, § 14 odst. 1 a 2, § 18 odst. 2 písm. b), § 22 odst. 3, § 24 odst. 4 písm. a), c), d), e), f) a g), § 25 odst. 1, 2 a 3, § 26 odst. 3, § 27, § 28 odst. 2, § 30, 36, 37 a § 39 odst. 4 a 5; however, it is obliged to take extra care not to jeopardize road safety.
(2) Drivers of other vehicles must allow the vehicle pursuant to paragraph 1 to ride or work and, depending on the circumstances, reduce the speed of travel or even stop the vehicle.
(3) Groups (columns) of vehicles of the armed forces or armed forces may be accompanied by front and rear vehicles using special orange warning lights. Accompanying vehicles must have the side and dipped beam lights on.