There are a few users reporting that Waze will not take them on the Exit 18 South bond on ramp to I-91 in Northampton off of Rte 5/Mount Tom Road. It appears that the on ramp is not connected to the Rte 5/Mount Tom Road.
https://www.waze.com/editor/?env=usa&lon=-72.62377&lat=42.30940&layers=2029&zoom=8&segments=22831467