Wow, interesting reading there.
This caught my attention: To travel the same distance as 1/gallon of Diesel takes 4.15/gallons of CNG
Plus a CNG tank is either 5 times or 9 times heavier (depending on what they say in text or show in a chart?) than a Diesel fuel tank.

BTU/gallon (approx.)
CNG = 23,000 - 34,000
LNG = 75,000
LPG (Propane) = 95,500
Gasoline = 112,000-125,000
Diesel #2 = 138,500

From Wikipedia:
Gasoline gallon equivalent (GGE) or gasoline-equivalent gallon (GEG) is the amount of alternative fuel it takes to equal the energy content of one liquid gallon of gasoline. In 1994, the U.S. National Institute of Standards and Technology or NIST defined "gasoline gallon equivalent (GGE) means 5.660 pounds of natural gas."[1]

If we paid an equivlent for BTU content, with Diesel as the standard at $4/gallon, then this is what the other fuels "should" cost:
CNG (Low) = 0.66 / gallon
CNG (High) = 0.98 / gallon
LNG = 2.17 / gallon
E-85 = 2.74 / gallon
LPG = 2.76 / gallon
Gas (Low) = 3.23 / gallon
Gas (high) = 3.61 / gallon