Question on Bruce Springsteen's lyrics

I have a question about the lyrics in Springsteen's Thunder Road...

"Lying out there like a killer in the sun" is versed in the context of driving to the promised land.  I don't get the connection and assume it's because there's something I missed in American popular culture.

Would someone please fill me in on the connection between the "promised land" and "killer in the sun"?

I've always read the "killer in the sun" as a lion or other beast sunning himself after a kill.  So Thunder Road is just lying there...laid out for them to travel.

Or I could be way off base!   

the penny finally drops.

Thanks for that insight, it makes sense now.