Waze automatically shows slow trafic when going too slow or not moving. In this case a pop-up should come up to confirm the heavy traffic. Sometimes I stop due to loading/unloading and waze shows traffic and reality is an empty road
Number one request on the wishlist website
krankyd is saying hopefully in 2.2
In the meantime you can mark the auto report as irrelevant and it will be removed from the server!
I am afraid 2.2 will bring us a pause-button indeed.
As no new user expects to see a pause-button on a navigation device, many will not KNOW when to use it. Others will not CARE to use it, and surely the most of wazers will FORGET to use it (especially now that Waze can run conveniently in the background on your iPhone). I doubt that it will be the right solution.
Personally, I like your suggestion, zzzp, with an addition though. I think Waze should simply ignore bumper-to-bumper-traffic - if it has not been preceeded with a gradual slowdown over the past minutes. Easy enough. I have never seen a trafficjam where you suddenly do not move at all - it may be 100 meters per minute, or even 30 - but you never come from full speed to a complete halt UNLESS you have gone parked. If Waze detects a standstill (without a hint of traffic in the minutes before), it should humbly ASK if you are experiencing traffic that you would like to report. Ready, problem solved. If it all was as simple like that (Yes Wayne, you can come in now)
Good points, but I must say that since the 50 slowest meters per segment are ignored, it almost does not happen anymore to me.
I @fvwazing. I really don’t know what the solution is. Although I will say iboften encounter going from 100 to 0 in 10 seconds 
I think a good solution would want a little human interaction as possible
I really would like to be able to sit with waze and plan routes and check connectivity and chit chat withou generating warnings of standstills around my block. A parked-up mode, enabled when you start Waze, until you start moving, seems good. Then I could enable it when I stop at petrol station and grocery store if I remember.
Dunno. Hope we get a great solution. As usual @fvwazing makes good points.