A battery powered driver for propelling a wheeled ground surface modifying machine, the driver comprising: at least one wheel (34A, B) contacting a ground surface; a battery powered electric motor; at least one pedal (38A, B) actuatable through a range; and at least one pedal sensor configured to output one or more signals indicating a degree of actuation of the at least one pedal within the range; a speed control input for inputting a constant speed level; and control circuitry configured to receive the one or more signals, receive the constant speed level, and manage delivery of electrical battery power to the electric motor to control a speed of the driver; wherein the control circuitry is further configured to: control the electric motor to accelerate the driver forward based on the one or more signals indicating actuation of the pedal within a first portion of the range, the power delivered to the electric motor for forward acceleration proportional to the degree of actuation of the at least one pedal through the first portion of the range such that the speed of the driver is variable based on the degree of actuation of the pedal within the first portion of the range; and characterized in that the control circuitry is further configured to: control the electric motor to accelerate the driver forward to the constant speed level based on the one or more signals indicating actuation of the pedal to a second portion of the range, wherein the second portion of the range is distinct from the first portion of the range, and the second portion of the range corresponds with further actuation of the at least one pedal with respect to the first portion of the range. at least one wheel (34A, B) contacting a ground surface; a battery powered electric motor; at least one pedal (38A, B) actuatable through a range; and at least one pedal sensor configured to output one or more signals indicating a degree of actuation of the at least one pedal within the range; a speed control input for inputting a constant speed level; and control circuitry configured to receive the one or more signals, receive the constant speed level, and manage delivery of electrical battery power to the electric motor to control a speed of the driver; wherein the control circuitry is further configured to: control the electric motor to accelerate the driver forward based on the one or more signals indicating actuation of the pedal within a first portion of the range, the power delivered to the electric motor for forward acceleration proportional to the degree of actuation of the at least one pedal through the first portion of the range such that the speed of the driver is variable based on the degree of actuation of the pedal within the first portion of the range; and characterized in that the control circuitry is further configured to: control the electric motor to accelerate the driver forward to the constant speed level based on the one or more signals indicating actuation of the pedal to a second portion of the range, wherein the second portion of the range is distinct from the first portion of the range, and the second portion of the range corresponds with further actuation of the at least one pedal with respect to the first portion of the range. control the electric motor to accelerate the driver forward based on the one or more signals indicating actuation of the pedal within a first portion of the range, the power delivered to the electric motor for forward acceleration proportional to the degree of actuation of the at least one pedal through the first portion of the range such that the speed of the driver is variable based on the degree of actuation of the pedal within the first portion of the range; and characterized in that the control circuitry is further configured to: control the electric motor to accelerate the driver forward to the constant speed level based on the one or more signals indicating actuation of the pedal to a second portion of the range, wherein the second portion of the range is distinct from the first portion of the range, and the second portion of the range corresponds with further actuation of the at least one pedal with respect to the first portion of the range.