short and sweet: have car pedals always had the
current configuration, i.e. clutch-brake-accelerator,?
For many decades, yes, but it was not standardized in the very early days. Model T’s had a pedal for reverse gear, a pedal for low gear, a pedal for the footbrake and a hand operated throttle, for instance.
I’d say it’s been more or less standard since the 1930s. The only prewar autos I’ve seen up close and personal were from Auburn, Packard, and Daimler Benz. All of them had pedal arrangements like modern vehicles. I’m not too sure about early '30s Frods and Chevys since every one I’ve seen has been modified far beyond its original appearance and new pedals may have been part of the change.
I’m somewhat curious about this now.
The Model T arrangement, more specifically, had a left hand pedal which disengaged for a neutral gear when held halfway down, low gear when pressed all the way down. The middle pedal was reverse, and the right pedal was the foot brake (there was also a hand lever that operated a rear-wheel brake)
I dug up the following description of the controls on the Buick Model 10, circa 1909-10:
The steering wheel levers were the throttle and spark advance. Note the different pedal order from the Model T arrangement.
Sometime between 1910 and the early 1930’s they generally managed to move from hand throttles to gas pedals, and got away from the idea of foot controls for gear shifting, though reverse pedals seem to have existed on a number of models, and still exist on some lawn tractors. A number of cars of the teens and early twenties vintages seem to have multiple hand levers mounted on the running board - I would guess that the “transmission bypass” described above for the Buick was a common arrangement.