Aww, my home town. I know I’m probably out of step with the majority here, but I’m OK with an idling ordinance. Unlike idiotic global warming regulations that have zero actual positive impact on anyone’s lives other than those who are in line for the slush funds, in this case, if you have a couple of heavy-duty diesel trucks and construction vehicles parked across the street from your house, unnecessarily idling all day long, there’s an impact there — noise, fumes, etc. Absent an ordinance, they’ll maybe shut it off when possible out of courtesy, or maybe they won’t, but I could see an ordinance being helpful in motivating people to do so as a matter of course. For the record, it would almost never be necessary to idle for heat or A/C in Palo Alto, it has one of the most moderate climates on Earth, made even more so by a lush tree cover across the entire city.
There’s a difference between idling in the street all day and being forced to shut you car off every 59 seconds in the drive through lane. Btw most cities already have laws about unattended vehicles idling that would take care of the vehicles that run all day.