Answers to Questions About New York An abandoned tool shed at 144th Street in Riverside Park. Q. While I (as a good Samaritan) was helping two groups of tourists at my local No. 1 subway station, the employee at the "token" booth refused to give me more than one subway map. How many maps does each booth get? Who is responsible for keeping each booth supplied? And, most important, what is M.T.A. policy about giving out subway maps to tourists? A.There is no set number, Deirdre Parker, a spokeswoman for the Metropolitan Transportation Authority's New York City Transit division, said in an email. "Generally, every customer in a group should get one," she said, "and although not written, we encourage agents to allow two per individual so as not to deplete the stock on hand too quickly. Local station supervisors are responsible to ensure that all booths have sufficient quantities of maps on hand. Q. This structure is in Riverside Park at 144th Street. A. The structure is a former tool shed and maintenance building, which has been in derelict condition for several years, Philip Abramson, a parks department spokesman, said in an email. It requires a new roof, a new door, some masonry work and electricity, he said. "N.Y.C. Parks and the Riverside Park Conservancy are interested in restoring this structure to support our horticultural care in the surrounding area," he said, adding that financing was not currently available. Q. This summer, Metro-North Railroad announced a track improvement project in the Bronx, in which hundreds of concrete ties would be replaced with wooden ties. Isn't this the reverse of what usually happens? A. The concrete ties are being replaced with wood for three reasons, according to Metro-North. "We have wood ties on hand, they are easier to install and they hold up better in water," Marjorie Anders, a spokeswoman for the railroad, said in an email. The comprehensive right-of-way improvement program began on July 1 in the Bronx between the Melrose and Woodlawn stations. Because of a proliferation of mud spots, Metro-North is rebuilding the entire six-mile, four-track section, including trenching to improve drainage. The problem is not with the quality of the concrete, but with water, Ms. Anders said. The section in the Bronx is in a "cut," below street grade. "So when it rains, water pours down from the street, and then it sits there," she said. The tracks sit on bedrock. Water pools around the 12 to 18 inches of ballast, the loose stones that hold the ties in place, and causes the ties to break down from beneath, she said. "Blame geology," Ms. Anders said. Concrete in standing water can be weakened by various dissolved sulfates, salts and other chemicals in the water and, perhaps surprisingly, wood can be more resilient. Ms. Anders pointed out that piers are generally made of wood, not concrete. In a mid-September progress report, Ms. Anders said Metro-North had finished work on two of the four tracks, removed 2,435 cubic yards of mud to improve drainage, removed almost 2,000 concrete ties, and installed 2,337 new wood ties and 815 tons of new stone ballast, as well as ridding the area of a lot of debris, garbage and graffiti.