Re: http://map.project-osrm.org/4c
The above route reports:
"Distance: 0.98 km - Duration: 4 min(s)"
With directions:
"1. Head southwest on Norvic Drive for 10 m
2. Turn sharp left on C801 for 330 m
3. Bear right on C821 for 640 m
4. Turn right on C183 for 1 km
5. You have reached your destination"
Summing the directions distances gives 1.98 km, yet the route distance is reported as 0.98 km.
Reverse the start and end points and the route distance is reported as ~1.68 km.