Based user experiences, the two main areas of improvement for Hubway are the kiosk and the general handle bar area on the bike, including the controls.
A larger, tablet size, multicolor touchscreen has higher contrast for easier visualization of both payment directions and allows display of detailed maps.
By moving the kiosk and the area map closer to eachother, it makes it easier to find where you are and where you want to go while purchasing a pass.
Removing on unnecessary screens would make the process of obtaining a pass less frustrating.
Using the sides of the kiosk to list rules of the road for biking (as well as other Hubway policies) would be a good use of extra large space, especially since many Hubway users are novice urban bikers and need this guidance.
Hubway did pilot helmet vending machines in 2013, although the outcome of that pilot is not clear. Incorporating a helmet vending machine into the kiosk would make the kiosk footprint larger but allow users to more easily obtain a helmet.
A better bell stays on top of handle bars, has contrasting coloring to show how to operate it and has a better use mechanism so that users don't have to take their whole hand off of the handle bar to use it.
Similar to the bell, a better gear shifter uses contrast to show function and more clearly signals the gear you are in.
Many people use their cell phones for navigation. A sturdy cell phone holder would allow people to safely use their phones for navigation while riding.