to drive at (a) high speed

[z7655431]

All the cars were driving at a high speed and drivers sometimes didn't stop for the traffic lights.
→Is this sentence correct? Is the phrase "at a high speed" used correctly? I think it should be "at high speed" (without a). However, the interesting thing is that Ngram and Google gave me different answers on this.

Please take a look at them:
https://books.google.com/ngrams/gra...,c0;,s0;;at high speed;,c0;;At high speed;,c0

https://www.google.com.tw/search?es....0..0.0....0...1c..64.serp..0.0.0.GaWQGXlNXG0

https://www.google.com.tw/search?es...2.2.0....0...1c.1.64.serp..0.2.82.KhDNoF-ci2o

 

[GoesStation]

Driving at a high speed is natural in the context. At high speed works in most other contexts, so it's not surprising that the latter phrase is more common.

 

[Tdol]

At a high speed could refer to a single occasion.

 

[Roman55]

Or to a particular speed.

I would not use the indefinite article in the original sentence.

 

[jutfrank]

This is how I understand the difference between high speed/a high speed:

It can be dangerous to drive at high speed. (generally fast)
For a motorist, 150 km/h is a high speed. (a specific speed, also fast)

Perhaps I'm overthinking this, but the inclusion of the reference word a in the example sentence suggests to me that the writer is referring to a certain speed (or speed bracket) that he/she has in mind. It brings a sense of specificity. That's what articles do.