unnecessary idleing

2. How long am I allowed to idle to warm up my diesel engine?
When the ambient temperature is below 25 degrees Fahrenheit, a motor vehicle may idle for 15 consecutive minutes when the vehicle has been stopped for 3 or more hours. Otherwise, idling is limited to 3 minutes. However, most diesel engines take 3 minutes or less to warm up (consult the engine manufacturer’s recommendations). Limiting idling will save fuel and money.

17. Who can enforce the regulations besides DEP?
Nearly all county health departments have been delegated authority to enforce the Department's air regulations, which include the idling standards. In addition, State and local police departments can enforce the standard on public roadways and on private property. Additional information on how to cite violations is available at http://www.stopthesoot.org/sts-idle-enforce.htm

18. Am I exempt from New Jersey’s idling requirements if my vehicle has been designated by CARB as a “Certified Clean Idle” vehicle?
The “Certified Clean Idle” designation and accompanying sticker apply to diesel vehicles of model year 2008 or newer, which are sold with diesel particulate filters. In California, no idling beyond 5 minutes is allowed, including idling for sleeper berth use, so vehicles with the “Certified Clean Idle” sticker are allowed to idle while the driver is using the sleeper berth only.
In New Jersey, only those vehicles with sleeper berths that have a model year 2007 or newer engine, or have been retrofitted with a diesel particulate filter, will be allowed to idle past the three-minute limit, but only while the driver is resting or sleeping in the sleeper berth. Idling is allowed if the vehicle qualifies for one of the listed exemptions specifically detailed in the idling regulation, N.J.A.C. 7:27-14.3(b)7 (http://www.state.nj.us/dep/aqm/Sub14_Rule.pdf).

21. Isn't it bad to drive a cold engine if it hasn't been warmed up?
Electronically controlled engines need no more than about 30 seconds to warm up. Driving a vehicle cuts warm-up times in half. The best way to warm up an engine is by driving it, while avoiding rapid acceleration and high speeds for approximately the first four miles in cold weather.