There is a blue van in the right lane,
*car in front of a blue road sign
at 270 km/h (168 MPH), he’s going to be right behind it in a second.
The bollards on the right side of the road are at a distance of 50m from each other, by which we can estimate that the other car is at least 250 to 300 meters away. 270km/h equals 75m/s so they are about 4 seconds behind (if the other car was stationary).
Therefore the lane is not – in fact – free.
To answer this question it is much more important to know what is on the right lane next to or behind the car, which we do not see in this image anyway.
Both of these options have their pros and cons, and I think it is important to explain these well to the council if you want to have any hope of convincing them.
A line of argument that has had some success in Europe is what has become known as "Digital Sovereignty", basically a fancy term for saying government should control its own infrastructure. So you might want to sell it as an easy way to have a permanent archive of public communication and a method for it that is under their direct control, rather than as a way to find more engagement.
As others have said self hosting has a maintenance and moderation overhead, but this can be lessened by running an instance together with other cities while still retaining most of the benefits of self hosting.
Seeing from the linked cross-post that this is about Port Alberni, and considering that http://portalberni.ca/ returns an empty reply while https://portalberni.ca/ lets me know I have been geoblocked because I'm outside of Canada and the US, I'd say you have an uphill battle before you though. These people made a website (probably paid for it, too), and then killed much of its use by geoblocking most of the world.
Good luck.