In built up areas, the default speed is 50 kph but can be 70, 40, 30 or 20 kph (the Mayor decides)! Usually signposted.
On Departmental Roads (A and B roads in the UK), the default speed is 80 kph. In some Departments (Counties) and communes the limit is 90 kph. If the road has more than 2 lanes (3 lane roads the 90 only applies to the side with 2 lanes in the same direction), the default speed is 90 kph unless otherwise posted. Unfortunately signposting is extremely poor so you don't always know what the limit is. It's an absolute nightmare which is why I use the Sat Nag (GPS).
On dual-carriageways, the default speed is 90 kph unless otherwise posted then it can be any speed from 110 kph - 30 kph! The lower speeds (70 kph and below) are usually enforced by RADAR.
Autoroutes are 130 kph except in the rain when they are 110 kph. Roadworks are usually 70 kph but, again, this varies.
LEZ (Low Emission Zones) are in all the major cities, not just Paris. In general level 0-2 can enter at any time. 3 and above is banned at times of high pollution - 3 is allowed in during low pollution periods, 4 and above - it depends on the city. Paris is trying to reduce vehicular traffic so they have more strict rules coming in (
https://urbanaccessregulations.eu/countries-mainmenu-147/france/paris):
Currently: Max is level 3 except at times of high pollution
- From 2022 - 2024: Max will be level 2. Level 3 and above banned
- From 2024: Max Level 1 (with exceptions for motos - level 2 allowed - Deauville (NT700) is level 2).
- From 2030: All petrol and diesel vehicles banned. Electric and hydrogen only!
As to Chinese Bat/pangolin Flu (regardless of strain), I believe it'll be summer 2022 (July-ish) before we in Europe are back to a semblance of normality. A good source of information is:
Dr John Campbell