A little math for commuter

Amber alert on hwy7 shows 8min to 55 and 14min to 94. Then when I reach hwy6, it shows 9min to 94 and xx to 101. So it takes 14 - 9 = 5min from hwy7 to hwy6. So it takes 8 - 5 = 3min from hwy6 to hwy55?

Why didn't they put the next sigh on hwy 55 instead? A nurser spent quite a few minutes and still cant figure out how old my daughter will be on the next visit they cant figure this out!