How many lanes?

A man walking along a beach finds a lamp, picks it up, rubs it and this genie pops out. The genie says, "For releasing me I shall grant you one wish! "The man thinks for a minute, and says, "I want you to build a bridge to Hawaii. I'm scared of flying and tend to get seasick. "The genie replies, "My good lad, do you realize how much it will take to do that? First of all, it will cost millions just to hire the workers. Not to mention all the materials it will take. In addition, there would need to be countless rest stops and gas stations and it would interfere with shipping lanes. I'm sorry, but it just can't be done. Please choose another wish! "The man thinks for a minute, and says, "I want to be able to understand women." The genie pauses for a moment and says -"So, this bridge you want...two lanes or four? "