Great question Whayes. Francis St is one of the main trucking routes for trucks to access the Westgate FWY and Princess FWY from the shipping docks and warehouses in Francis St and Sommerville Rd and the areas surrounding.
That said, there is a curfew of 8pm to 6am. This means trucks are unable to use the route during these times which significantly lowers the air and noise pollution. So if you work during the day, this may not be a big issue for you. If you are a family with family members staying at home for long periods of time, this may cause some concern.
I agree with Maroage, housing on the opposite side of the road will definitely be more convenient for many reasons, however the price is more expensive because of it. So if you are on a budget, this area is a good place to start, though if you are a little more under your belt, then I would suggest towards Hyde St instead of Francis.
Is there a reason why you have chosen Yarraville in this case? Are you considering other surrounding areas?
trucks will aventually be a thing of the past in francis st, well, there will be no more trucks then on any road when the yarraville gardens project gets underway, the truck depo's will be moving, so the docklands container traffic will be diverted.
if the banks haven't got you by the googlies, then buy buy buy!
Personally I would say to live on the other side of Frances St, Better resale value, easier access to the village and overall easier walk to the station. Either way if the choice was to live there or a back street of spotswood I would still live in Yarraville (if comparing to similar streets)