I'm rare. I don't mind city or gridlock traffic with a manual tranny.
I've been driving one for over 15 years and think I've got it down pat. My current car is a Nissan SpecV with a QR25DE engine and 6-speed tranny. The car's EPA rating is 23/29 and I've gotten over 30mpg on some tankfuls. So, When I drive in a fair amount of low speed traffic, my mileage still doesn't drop below 26-27mpg ... as long as I'm not stopped for too long.
Basically, I drive in stop-and-go traffic close to idle RPM. With modern engine management systems, the engine won't stall if you are careful with your transitions. In gridlock, I'll idle in 1st gear as long as there is room ahead of me. And when traffic starts to move ahead of me, I get going ... but no jackrabbit starts. It's likely it will slow down again a few hundred yards up the road, anyway.
In slow traffic during snowstorms, I have idled the car in 2nd and even
3rd gear for miles. Never touched the gas or the clutch. It's all about thinking ahead and pacing yourself.
I work in a downtown area without a set parking spot/lot so I have spent up to 35 minutes circling the blocks looking for parking. But because I drive sensibly, this driving doesn't seem to hurt my fuel economy at all even though it's mostly in 2nd or 3rd gear.
There is a similar car to mine out there with the same engine but tuned for a bit less HP (165hp vs. 175hp) and people (often kids) driving these cars complain of fuel economy as low as 23mpg.
--- Bror Jace