This software provides a prescribed routes for driving which is proved to be a hyper-efficient practice which reduces idling of truck and also provides shortest route to reach destination by avoiding left turns. With 95,000 trucks delivering packages every days provides economies of scale. Hence this improvisation have significant impact on overall delivery time and saving on fuels.
Safety - http://www.businessinsider.com/ups-efficiency-secret-our-trucks-never-turn-left-2011-3
Savings 2012 - http://www.bloomberg.com/news/2012-09-20/ups-makes-no-left-turns-in-quest-to-deliver-sustainability-q-a.html
Savings 2007 - http://www.nytimes.com/2007/12/09/magazine/09left-handturn.html?_r=0