At Project Gutenberg, "Sense of Obligation" by Harry Harrison (originally published in Analog, 1961)."It took a very special type of man for the job—and the job was onerous, dangerous, and the only really probable reward was disaster. But when a man who says he knows it's going to kill him asks you to join.... "
Available for your favorite ebook reader or computer HERE.
At Mars & la Science Fiction, "Lost Treasure of Mars" by Edmond Hamilton (Aug 1940)."Garth Crane faced death because of one treasure cache. Was it a good idea to gamble his life on the chance of finding a greater one?"
Available via Marooned - Science Fiction & Fantasy books on Mars HERE.
At Tor.com, "The Go-Slow" by Nnedi Okorafor. This story was "first published in the mixed original-and-reprint anthology The Way of the Wizard (Prime, 2010), edited by John Joseph Adams.""It was Nigerian style gridlock. The worst kind of traffic. It was a carnival of vehicles from cars to supersize trucks, nose to ass for miles, oozing, spewing, dribbling exhaust into the weighted heat under the hot penetrating African sun."
Online HERE.