Want to save gas? Do what the professionals do. Make the right choice. Literally. If you want to squeeze the most out of each gallon of gasoline, turn right whenever possible.

UPS drivers have been doing it for several years and they say the savings are substantial. "UPS drivers are trained to map their routes to turn right whenever possible," UPS spokeswoman Kristen Petrella said in a telephone interview. "It saves fuel and reduces emissions by minimizing the length of time our trucks are idling. And it's safer too, because you don't have to cross traffic."

With left turns more time is spent idling while waiting for oncoming traffic, and right-on-red regulations also help save fuel.

Petrella said UPS managers used to drive around to find the routes with the most right turns. Now they have a combination of not just experience but computers, codes, and programs that allow them to plot out right-turn routes in seconds.

Petrella said the company estimates that in 2007 the company saved 3.1 million gallons of fuel, and avoided discharging 32,000 metric tons of emissions into the air by turning right whenever possible.

"Our drivers are so accustomed to driving right, they say it's difficult for them to turn left when they're off duty," she added.

This may suit you to a T

It's going to take more than just turning right to take the sting out of prices at the pump.

If you're wondering how much you'll save by leaving the car in the garage and taking public transportation, check out the "transit calculator" at the MBTA's website, mbta.com.

You can plug in your car's miles per gallon, the price of gas, length of commute, and parking cost, and it will calculate your yearly commuting costs. Then compare it with what it would cost to take the T.

Congestion ahead

Commuters on Interstate 495 can expect more company in the coming years, according to a study released last month.

For the past two years, the I-495 Study Committee composed of representatives of the Executive Office of Transportation, the North Middlesex Council of Governments (representing Lowell area cities and towns), and the Merrimack Valley Planning Commission has been examining congestion along the 40-mile stretch of highway from Westford to Salisbury.

A study conducted for the group predicted that by 2030, there will be another 20,000 cars per day clogging the already congested road.

The group is examining a number of alternatives to relieve congestion along the corridor, including widening the highway.

Starts & Stops appears every other Thursday in Globe North. Transportation comments and questions may be sent to starts@globe.com.

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