Travel times too low

Discussion created by edsmega on Nov 11, 2010
Latest reply on Nov 12, 2010 by jsandhu-esristaff
I did a CLOSEST FACILITY analysis and I am finding some of the travel times are too low although the miles calculated seem ok.  On one route it computed a 16 minute travel time when mapquest computed 22 minutes and the actual drive time is 28 minutes for the same route. A calculated time of 1/2 of reality is just not close enough.

On the LAYER PROPERTIES display under tab ATTRIBUTE PARAMETERS there is a parameter column of MPH values and a value column that I assume is the speed that is used in the calculation.  There are NO ENTRIES for 60MPH or 65MPH - common freeway speeds here.  Could it be erroneously using the default of 5mph for the ALL OTHER ROADS category?

What should I do to get these travel times more realistic? or at least in line with the values produced by Mapquest which seem to be closer to reality?

I assume this problem is also distorting my service area polygons.

I am a rookie at this - I hope I am just doing something dumb that can be easily fixed.