design speed vs designed speed

Both 'design speed' and 'designed speed' are correct, but they are used in different contexts. 'Design speed' refers to the speed at which a road or highway is intended to be safely traveled, while 'designed speed' is the speed at which a vehicle or road is specifically engineered to operate. They are not interchangeable as they convey different meanings.

Last updated: March 26, 2024

design speed

This phrase is correct and commonly used in the context of road engineering to refer to the intended safe speed for a road or highway.

Use 'design speed' when referring to the speed at which a road or highway is intended to be safely traveled.

Examples:

The design speed of this highway is 70 miles per hour.
Engineers consider the design speed when planning road improvements.

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The mean contact force of each pantograph shall fulfil the requirements of the point 4.2.11 up to envisaged design speed of the OCL under test.
design speed not exceeding 30 km/h when the brakes act not on all wheels;
The load capacity may be adjusted in relation to the maximum design speed of the trailer in agreement with the tyre manufacturer.
I Tyres shall be type-approved according to the requirements of UNECE Regulation No. 54 even if the design speed of the vehicle is less than 80 km/h.
Whereas an appropriate increase in the design speed is from 30 to 40 km/h;
These measurements shall be carried out with an Interoperability Constituent pantograph installed on rolling stock exhibiting the mean contact force characteristics as required by clause 4.2.15 of this TSI for the envisaged design speed.
The unit shall be designed to provide safe movement up to the maximum design speed.
vehicles with a maximum design speed not exceeding 6 km/h;
Contact wire uplift at the design speed shall comply with the stipulations in Table 4.2.16.
The maximum design speed of the vehicle is measured in accordance with the requirements set out below.
Information document concerning the essential characteristics of the vehicle type that affect its maximum design speed
Calculated maximum design speed:... km/h
at the maximum design speed with the transmission in neutral,
Most passenger cars today have a maximum design speed in excess of 140 kilometres per hour (km/h).
300 km/h or the maximum design speed, whichever is lower
Electric units that require more than one pantograph raised in operation and of maximum design speed higher than 120 km/h shall be equipped with an ADD.
On vehicles with a maximum design speed not exceeding 30 km/h, the service braking system shall act on all the wheels of at least one axle.
Deviations from the prescribed test procedures are permitted in case that testing conditions cannot be complied with due to a too low maximum design speed of the tractor.
maximum design speed <= 25 km/h and
maximum design speed <= 45 km/h and

Alternatives:

intended speed
planned speed
projected speed
target speed
desired speed

designed speed

This phrase is correct and commonly used in the context of vehicle or road engineering to refer to the speed at which a vehicle or road is specifically engineered to operate.

Use 'designed speed' when referring to the speed at which a vehicle or road is specifically engineered to operate.