Do you have 2018 speeds for period November 2017 to Jan 2018 to compare? Can you also annotate these more recent winter months on the graphs? It is the traffic flows over this winter that seem to be particularly slow and traffic jams eastbound at night used to occur sometimes but they seem to be occurring all the time now.
Can you also provide historic average speed shown as well on the graph as this ties in with may view (and other FOI information requested) that the M74 junction design is causing chaos to traffic flows on M8.
Has there been an increase in traffic using the road?