Have protest movements made any difference to transport? – transportxtra

Protests are a waste of time; they never change anything. I read comments like that online as protestors in tunnels obstructed the HS2 works earlier this year. I have heard similar views expressed many times in the past, usually from people who disagree with protestors. Does the evidence support those views?
Since the late 1980s transport has provided several test cases. Over three years, 52 interviews and thousands of documents, I set out to find some answers. The result was two research articles and a paperback book, Roads Runways and Resistance. 
The short answer is that protest movements have influenced the course of events, although it is difficult to predict success or failure in advance. Researching the project led me in unexpected directions; I did not expect to be writing a crime or spy story, which is what it became in parts.
One way protest movements can influence events is by shifting the ‘Overton Window’, the range of ideas discussed in the mainstream media and considered legitimate by politicians and public
What makes policy change?