This is just one instance of OK-270 being misshielded
as US-270 along this route. Understandable, because until just a few years
ago this used to be US-270. The US route now remains duplexed with I-40 until
far west of Oklahoma City.
Eastern Terminus: US-177, just north of I-40 junction
Confusion continues along US-177, as there are several
instances a little south of here of US-270 being referred to as OK-270.