Construction traffic in Lyons?

First, despite the British predilection for adding it, there's no "s" in Lyon. You're batting .500 between your title and text.

Here is the ONLYMOOV website provided by the Lyon Métropole showing major work zones (chantiers).

You can use a drop down menu to find a list of big projects (les grands projets), or just the list of chantiers if you provide the commune in which you're interested. Easier still is finding where on the map you plan to be and click on any projects that may be depicted in that area. When you do that, the name of the project will pop up and you can learn more by clicking on the link for En savoir plus (learn more).

Bear in mind that a major, multi-year construction project is in its early stages to expand the vastly overcrowded Gare de Lyon Part-Dieu, and my wife, who took the train down to Lyon last week to visit a friend for a few days, mentioned that some construction work on that project has begun.

If you're going to be using mass transit, especially buses and the Metro, you shouldn't have much trouble.

If you were thinking of driving in Lyon plan on major headaches -- and that's just for the normal traffic and crazy Lyonnais drivers. Multiply that by an irritation factor to account for the construction projects.

My advice? Unless you're very comfortable driving in European cities and dealing with double parkers, crazy pedestrians that walk close in front of moving cars and behind cars backing up, narrow one-lane streets blocked by large delivery trucks, motorcycle and scooter drivers who ride as if they think they're invulnerable as well as having magical powers of speed and the ability to ignore prevailing traffic laws, then, well, I'd stick with transit. It's reasonably priced, pretty good (especially with the TCL app) and will get you where you want to go. If the day is hot, though, I'd stick to the buses. The Metro is not air conditioned and riding it on a sweltering day can give you a pretty fair idea of how the sardine felt when he was packed in the can with his buddies and was just starting to be heated up before the can was sealed shut. Shouldn't be much of a chance of that in October, but just in case, I thought I'd mention it.

Not sure what you plans exactly are ; I imagine that could matter ; if just driving into or out of the city once or twice it is not going to be major concern.

I recently (in July) took a train into Lyon TGV (Part Deux) train station, renting a car and drive out of the city mid-day on a weekday ; headed out on A43.
No odd traffic issues or construction abnormal concerns.
Like most city's there was a stressful moment or two before getting to the highway but overall no problem.