Thank you. This works well, regardless if the vehicle's actual location will be plus or minus the pre-determined coordinates I'll be comparing against.

Mock up:

use warnings;
use strict;
use feature 'say';

use constant {
    ACCURACY    => 1e5,
    RANGE       => 1.2,
    LON         => -119.31665,
};

my $lon_current = -119.31666;

my $deviation = abs(ACCURACY * (LON - $lon_current));

say "Within range: $deviation" if $deviation < RANGE;
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