Because the Second Avenue subway line is years away, and because 54,000 people use the bus routes up and down First and Second Avenues, the city’s Transportation Commissioner is drastically changing traffic on those boulevards. “We are basically building a surface subway,” said Janette Sadik-Khan yesterday, explaining that the two avenues, from Houston to 125th Streets, will have bus-only lanes. Altogether the lanes will stretch twelve miles, and will be policed to ensure that cabs and other cars do not use them. Bike lanes will also be added, which will reduce the amount of lanes for other drivers — but Sadik-Khan says that separating the buses and the bikes from the cars will create a more efficient system. Also to speed up bus travel, which in some parts of the city is statistically known to be slower than a swiftly walking chicken, riders will be able to swipe their MetroCards on the sidewalk before getting on the bus.