Maximum and minimum speed limit signs

Maximum speed limit sign

Article 3 of the National Technical Standard QCVN 41:2019/BGTVT on Road Traffic Signs defines it as follows:

The maximum permitted speed is the highest speed allowed on a road, section of road, or lane as stipulated by the competent authority. Drivers are not permitted to operate their vehicles at speeds higher than this limit.

Maximum speed limit signs are used to restrict vehicle speeds on certain accident-prone road sections.

Identifying different types of speed limit signs

Based on the National Technical Regulation QCVN 41:2019/BGTVT issued with Circular 54/2019/TT-BGTVT, the group of maximum speed limit signs includes the following signs:

1.1. Sign P.127 “Maximum permitted speed”

This is a typical example of a prohibition sign. The maximum speed limit sign is circular, with a red border, a white background, and red numbers in the center indicating the maximum permitted speed (in km/h).

Traffic sign P.127 is used to indicate the maximum permitted speed for motor vehicles. This sign prohibits all motor vehicles from exceeding the maximum speed indicated on the sign, except for priority vehicles including:

- The fire truck is on its way to work.

- Military vehicles, police vehicles on emergency duty, convoys with police escort.

- The ambulance is on an emergency mission.

- Vehicles used for dike maintenance, vehicles used for disaster relief, disease control, or vehicles used in emergency situations.

Speed ​​limit signs are usually placed on roads passing through densely populated areas, areas with heavy traffic, construction sites, etc., where speed limits for vehicles need to be imposed.

1.2. Sign P.127a “Maximum permitted speed at night”

This sign is rectangular in shape, with a red-bordered circular drawing on a black background and red numbers inside at the top; the bottom indicates the speed limit time.

Sign P.127a is used to indicate the maximum speed allowed for vehicles at night.

This sign is placed in densely populated areas to encourage speed limits when traffic is light. Drivers at night who see this sign are not permitted to exceed the speed limit indicated on the sign, except in priority cases as stated in section 1.1.

1.3. Sign P.127b “Combined sign indicating maximum permitted speed on each lane”

This sign is rectangular in shape, with a blue background, and inside are white arrows pointing upwards. Each arrow has a white circle with a red border and a number indicating the maximum permitted speed.

The combined speed limit sign for each lane specifies the maximum speed allowed for each lane. Vehicles traveling in a particular lane must comply with the maximum speed limit allowed for that lane.

Minimum speed limit sign

The minimum permitted speed is the lowest speed allowed on a road, section of road, or lane as prescribed by the competent authority. Drivers are not permitted to operate their vehicles at a lower speed when traffic conditions ensure safety and allow for a higher speed.

Point D.6 of Appendix D of the National Technical Standard QCVN 41:2019/BGTVT on Road Traffic Signs also stipulates the following:

D.6 Sign R.306 “Minimum permitted speed”

a) To indicate the minimum speed allowed for motor vehicles, place sign R.306 “Minimum Permissible Speed”. Accordingly, the minimum speed sign is a sign indicating the lowest speed that vehicles must achieve on a road, road section, or lane as prescribed by the competent authority.

When encountering this sign, drivers are not permitted to operate their vehicles at a lower speed unless traffic conditions allow for a higher speed.

According to point D.6 of Appendix D of the National Technical Standard QCVN 41:2019/BGTVT, minimum speed limit signs are mandatory for all types of motor vehicles to operate at a speed not less than the value indicated on the sign under favorable and safe traffic conditions.

Vehicles whose maximum speed as specified by the manufacturer does not meet the minimum speed indicated on the sign are not permitted to enter the road marked with this traffic sign.

The minimum speed limit indicated on the sign is in km/h and is regulated according to the technical standards of the road and bridge and traffic organization; it must not exceed the safe speed limit.

Typically, minimum speed limit signs are only applied on road sections where traffic capacity needs to be increased, outside of densely populated areas, where vehicles travel at high speeds.

If a driver sees traffic sign R.306 with the number 50, 60, or any other number and it is white, the driver must drive at a speed equal to or greater than the speed indicated on the sign; otherwise, they will be subject to administrative penalties.