My cat will allow brief chest pets. NOT belly rubs!!!
Mostly I think she just wants me to stop walking and give her my full attention. She flops right at my feet. Usually while I'm carrying something.
Sometimes she'll let me touch her paws too, NOT in a grabby way, just with my fingertips.
(She normally allows face scritches and back pets but this position isn't conducive.)
And sometimes I just take a few seconds to tell her good things about herself, like she's smart and pretty and brave and strong.
Fortunately, cats are cool with the attention only lasting a few minutes.