Hello molder
Yes, two sources hereunder expose that dimension, I visited Malta more as a tourist and had no meter to check personnaly with good accuracy.

The cart ruts of Malta: an applied, geomorphology approach
Derek Mottershead, Alastair Pearson & Martin Schaefer∗
"The mysterious rock-cut cart ruts ofMalta are here examined by geomorphologists. They find that
the ruts could be caused by two-wheeled carts with a gauge of 1.40m carrying moderate loads. In
wet weather the carts would gradually cut into the limestone and reach their ground clearance of
0.675m, causing the carriers to try another route – so there are plenty of them."

Cart-Ruts and their impact on the Maltese landscape, by David Trump
"The gauge, the distance between tyhe two ruts of a pair, varies only slightly, around the average of about 1,41 meter, only 3cm less than the standard railway gauge of 4'8_1/2.
A very puzzling detail (..) is that even the gauge of an individual pair can be a couple of centimeters more or less at different points along its lengths."