Usually, 辺り vaguely points a referent in space or in time. E.g., a vague reference in time is:
They learn division in the arithmetic class around the third year in Japan.
I just checked so I know exactly that it is in the third year of elementary school (comprising of children reaching 8 years of age during the school year that begins in April) that children are taught how to divide, but people easily forget the school curriculum they or their children have been taught in. 辺り is useful to convey the attitude that it must be around the third grade, but you are not sure.
Likewise, it is hard to tell exactly (or just) when a car comes at the foot of a hill. A level road insensibly mingle with slopes that would soon turn out to be part of the hill. Perhaps this is the motivation behind using 辺り here. It also echoes the 辺り in Risson's speech. He is not choosy about his drop-off point, just wants somewhere around here.