If you stop in traffic between 50mph average speed cameras can you then drive above the limit?

We were stopped in a 50mph average speed limit roadworks for 20 minutes. My co-driver maintains that she could drive much faster than 50mph as only the average speed was being measured over the distance - in other words, no need to stick to 50mph. It sounds logical but is that legal

Asked on 2 April 2019 by Stanley Field

Answered by Honest John
You have to average 50mph or less between each of the cameras.
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