There's this portion where there are 3 massive hills in a row, very steep and I do manage to cycle up them but they reduce my average speed. And then a few times I have to stop because there is a junction and I rather just stop and check then get run over by accident. And I go through about 6 sets of lights on that route.. Which all contribute to a decreased average speed. I guess I could try going faster on the flat portions of the ride. The route is 1000feet and 45km.If you can do your route at say 20kmh - go out and attack certain parts of it as fast as you can. Then recover for a bit and go again.
If you do this you stress your system and it adapts to cope with the pace. You will get faster.