I think every city needs to have bike lanes and I really love Monsterfurby's awesome idea to add bike rent stations to the game. In CIM1, I did that using the bike racks and the parking ticket automats - okay, decoration only, no function, still enhancing the realism and beauty of my cities IMHO. In CIM2, I'm using bus lanes as bike lanes when building my roads. Which actually makes sense, as in Frankfurt, where I live, ciclysts are allowed to use bus lanes (unlike cars).