Also "interfering with car traffic" is silly. Bikes are traffic too and have just as much right to being in the road as cars.
That's 40 km/h. Are you trolling or is that a typo?
I've been bicycling nearly daily for >45 years and I've never gone that fast.
I cycle to work daily (22km) and have cycled pretty much all my life since. Sustaining 40km/h for longer periods is unrealistic if 1.) your terrain is not completely flat; 2.) there is wind; 3.) you do not want to get to your destination soaked with sweat; 4.) you have to carry some luggage like a laptop; or 5.) you cannot use a touring bike because of the terrain.
I sometimes cycle with a GPS and have Pedelecs (limited to 25km/h for electrical support in Germany) as a reference point. The vast majority of cyclers that I encounter cycle less than 25km/h under normal conditions [1]. Probably somewhere between 20 and 25. If there is strong wind or uphill, it's definitely less than that.
My 20 km/h includes a few stops and normal traffic so it's probably closer to 30 on a flat straight with no traffic. Perhaps a special bike with narrow tires could help, but that's less versatile (and I need to ride on dirt roads too).
The highest I've measured is 54 km/h, on a big down hill pedalling full strength on top gear. I regularly exceed 30 km/h but not for sustained periods.
I could probably do 40 km/h for 15-30 minutes if I went all-in and had a racing bike. But my commute includes dirt roads and pathways through the forest so a racing bike is out of question and I don't want to take a shower every day arriving to work.
I don't really have to share the road with cars at any point on my commute so driving too slow isn't an issue. A part of the way is shared with pedestrians (and slower bicyclists) so going too fast is more of a problem.
I've used a good recumbent bicycle and I could actually hold 35 km/h easily in that one, in the same place I usually average 23 km/h upright with an ordinary ~$700 city bike.
These are mostly 2-lane country roads, with 6 foot drainage ditches on the sides on the roads instead of sidewalks, and sometimes even large delivery semi trucks drive these. You'd have to be crazy to ride a bicycle on such a hostile road. I did so twice and my mother refused to let me bicycle to work, insisting I use my father's car.
There is a huge difference in both perceived and actual safety between being part of a large group of bicyclists that occupies a significant fraction of the lane and being a lone bicyclist going along the verge of the road while cars and trucks pass you at 65 mph.