How can one maintain Kavanah reciting Keriath Shema' while walking along the way? Or is the requirement waived in this case?
This allowance is for someone to say the shema when he is already "on the path". In such a circumstance, he will have more concentration if he says shema while continuing his journey than if we make him stop and delay his trip. For example, see Shulchan Aruch OC 183:11.