Traffic stops at the minute are really poor at times. Depending on the time of day and who pulls you over, sometimes you'll have to sit idle for 5-10 mins while they get backup, and its not just waiting for another officer, its waiting for multiple units. I could do 100 in the city and have 5-6 cops on me at a traffic stop. Whilst there will be arguments that this is realistic or justified in some scenarios (which it can be), the rate it happens right now just kills any fun. Unless there is a specific RP reason, there is no need for more than 2 units at a standard traffic stop.
The loadouts cops have for basic patrols is kind of unrealistic too. For example, if you're sitting on the highway doing speed traps, there is no realistic reason, regardless of rank, to be sitting there with multiple sets of body armour and assault rifles. Your loadout should match the activity that you are doing. Pump shotguns whilst pulling up to a bank robbery = fine, pump shotguns for handing out speeding tickets = overkill. This coupled with my first point, makes every interaction boring unless you're willing to drive around with 100k worth of gear that you are willing to lose everytime.
Also +1 to Userone above, was gonna mention it but they've summed it up pretty well.