It's Dump the Pump Day in Brooklyn and around the country, and drivers are being urged to ditch their cars for the day. The American Public Transportation Association, the MTA, the Sierra Club and the Natural Resources Defense Council are all calling on people to use public transportation for the day instead of driving. With gas prices averaging $3.78 per gallon in the city, it's a good way to save a little money. The latest transit savings report says a two-person household that downsizes to one car can save about $10,000 per year.