1. This highway isn't very busy 2. At 2:08 the Franklin McKay Bridge has a speed limit of 50 km/h (31 mph) which makes that bridge a major bottleneck of the highway. I think you could use TMPE to increase speed limits. Also, the bridge is only 4 lanes wide, which is not very good.
Amazing stuff! Love the idea of having a country with all your cities in it, and how detailed it is, could you maybe do something more general about the country, as to give a general overview?