May be a number in some part of the screen where you can see the ping, is that possible? With that you know what you are facing or call a vote reset
You can already see a ping on the server selection screen. Beside, in my experience, you don't want to rely on a ping number that much, sometime your ping gets high, but the game can still be easily played.
Beside, if your ping is high, a server reset likely won't fix it because the server lagging and you lagging are two very different things.
Here is what I suggest you do if you experience lag. First, try to initiate a vote reset, 3 people are needed to initiate a reset vote, so you can always try asking a few people if they are also lagging, and if yes to call a vote reset. Take note that you lagging doesn't mean everyone is lagging, so you won't necessarily be able to get a reset vote going.
We've been using that system for a long time now, it does the job fairly well and I don't think we need any other tool or system, specially not anything that implies monitoring each player to detect lag, that would likely cause more lag as MAB said.