Public enquiries continued through the 1970s and 1980s. Each section had its own enquiry, where local citizens and interest groups could question the plans. In all, "39 public inquiries before independent Inspectors were held, taking over 700 sitting days – with many more working days (and nights) preparing evidence". Objectors could put forward alternatives, and each of these had to be answered with presentation of evidence. Evidence included predictions of traffic and events which would affect growth of traffic. Enquiries and evidence were open to public scrutiny and debate.