US-36 becomes I-72 at Hannibal, Missouri, as the road crosses into Illinois. To Lisa's annoyance, there are no rest areas along this stretch of I-72, because she was definitely needing rest. She spent a restless few hours in a parking lot near Springfield before moving on and calling me from the Pilot Truck Stop in Decatur. (Ironically, there is a rest area just east of Decatur, according to IL-DOT's web site.)
She thought of refueling before turning in -- there was a gas station that will accept her card within sight of the parking lot -- but decided to put it off until getting up in the morning. To her considerable disgust, she awoke to find that the price of gasoline had gone up overnight from $3.86 to $4.06/gallon.
Lisa also observed that the reason it's taken so long to install milepost markers on California highways is that Nebraska used them all up by posting them every two-tenths of a mile. (Those who have not driven in California may not be aware that California has lagged seriously behind the rest of the USA in adopting the milepost numbering of roads and exits.)