On which model of travel do more people use smartphones, tablets and e-readers: inter-city trains, inter-city buses or airplanes?

You might guess usage is highest on airplanes, possibly on trains.

In fact, a study of use of personal devices on buses, trains and airplanes suggests there is no “digital divide” among passengers on all those modes of travel, but also that usage is highest on inter-city buses.

On Greyhound inter-city buses, the use of personal technology is now significantly higher than on airplanes and is only marginally below that of Amtrak and discount bus lines, a study by the Chaddick Institute for Metropolitan Development has found.

In fact, for the first time in five years, use of personal devices on at least one inter-city bus service was higher than on airplanes or Amtrak.

Among the 505 passengers observed on 20 Megabus and Van Galder buses operating from curbside locations in 2013, 59 percent were using technology, compared to 46 percent in 2012.

In large part, that might be because the amount of use of new “connected” bus services -- which offer travelers uninterrupted cell phone signals as well as free Wi-Fi and power outlets -- grew 30 percent between 2012 and 2013.

On Amtrak, the share of technology users was flat at 52 percent in 2013, the study found.

Availability of power outlets, Wi-Fi and mobile access likely explains the lighter use of personal devices on airplanes, according to the Technology in Intercity Travel Study.

Technology use on airlines remained virtually flat and continues to lag behind other modes in 2013, suggesting that lack of communications “for no incremental cost” is an issue.

But the ban on phone calls aboard aircraft, as well as the lack of power outlets, likely also are issues.

The two fastest growing modes of intercity travel over the calendar years 2012 and 2013—intercity trains and discount buses—were also those in which the technology use was observed to be the highest in early 2013.

The amount of discount bus service grew by four percent between 2012 and 2013, while the number of Amtrak seat-miles grew by 1.4 percent, as did airline seats.

Availability of Wi-Fi and mobile Internet connections, the “no incremental cost” access and lawfulness of device app use on trains and buses possibly explains the higher use of personal devices on buses and trains.

Mobile device connections are disabled in the air, in addition to currently being unlawful on most flights. When Wi-Fi is available, usage requires payment, and power outlets often also are not available.

But there seems to be no “digital divide” between passengers on inter-city buses, trains or airplanes.