Engineering English
Design Speed
Civil Engineering · Last updated: July 30, 2026 · How this entry was written
Definition: Design speed is the maximum safe speed that can be maintained over a specified section of highway when conditions are so favorable that the design features are the governing factor.
Example in context
“The design speed of 120 km/h was chosen for this rural freeway to match the terrain and anticipated traffic behavior.”
“Bu kırsal otoyol için 120 km/s tasarım hızı, araziye ve beklenen trafik davranışına uyacak şekilde seçilmiştir.”
Where engineers use it
Design speed influences many geometric elements such as curve radius, superelevation, sight distance, and lane width. It is a fundamental parameter in highway design standards and ensures consistency and safety.
Synonyms: design speed limit
Practice: can you use “Design Speed” at work?
You are designing a new highway through rolling terrain. The expected traffic includes heavy trucks. How would you determine the appropriate design speed and what trade-offs would you consider between safety, cost, and driver expectation?
Show a model answer
“Select an appropriate design speed for this mountainous highway section.”
“Design Speed” in 21 languages
| English | Design Speed |
|---|---|
| Turkish | tasarım hızı |
| French | vitesse de conception |
| German | Entwurfsgeschwindigkeit |
| Spanish | velocidad de diseño |
| Chinese | 设计速度 |
| Arabic | سرعة التصميم |
| Portuguese | velocidade de projeto |
| Russian | расчетная скорость |
| Japanese | 設計速度 |
| Italian | velocità di progetto |
| Vietnamese | tốc độ thiết kế |
| Hindi | डिज़ाइन गति |
| Thai | ความเร็วออกแบบ |
| Indonesian | kecepatan rencana |
| Korean | 설계 속도 |
| Bengali | নকশা গতি |
| Dutch | ontwerpsnelheid |
| Swedish | dimensionshastighet |
| Finnish | mitoitusnopeus |
| Ukrainian | розрахункова швидкість |
Frequently asked questions
What does Design Speed mean in engineering?
Design speed is the maximum safe speed that can be maintained over a specified section of highway when conditions are so favorable that the design features are the governing factor. In Civil Engineering, the term carries a usage-frequency rating of 10/10 in the Engineering English library.
How do you pronounce Design Speed?
Design Speed is pronounced /dɪˈzaɪn spiːd/ (IPA). The Engineering English app plays audio for the term and checks your pronunciation with speech recognition.
How is Design Speed used in a sentence?
Example from an engineering context: “The design speed of 120 km/h was chosen for this rural freeway to match the terrain and anticipated traffic behavior.”
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