In the mid-1960s the department adopted a dark blue and white color scheme, similar to that on cruisers commonly referred to as a "black and white". The department purchased several different brands of cruisers over the years including the Dodge Monaco, Chevrolet Impala, and Ford Crown Victoria. These vehicles, like their modern counterparts, were full-size to facilitate prisoner transport and were manufactured as "special police" vehicles. These vehicles had heavy duty suspension systems to meet the rigors of police driving, more powerful engines for emergency response and pursuit purposes and had heavy duty electrical and cooling systems to support the use of emergency equipment such as blue lights, sirens, radar and two-way radio systems. These cars were equipped with screens between drivers and passenger compartments to afford the officers protection when transporting prisoners. From the late 1980s to 2012, the department exclusively used the Ford Crown Victoria Police Interceptor as its marked patrol vehicle. In 2012, Ford discontinued the Crown Victoria Police Interceptor. The department has since transitioned to the Ford Explorer Police Interceptor and purchased three in 2012.

In the mid-1990s, shortly after the appointment of Chief Russell P. Sienkiewicz, the department decided that a change in the color scheme of its marked cruisers was in order. This was precipitated in part by the large number of similarly marked cruisers from other departments coming into the City to go to the courts, state hospital, county jail, VA Medical Center and Cooley Dickinson Hospital. It was difficult for members of the community to distinguish which were and were not Northampton cruisers. In response to the need to be more readily identifiable to the community, the current white cruiser with full-length blue stripe color scheme was adopted and has been in use ever since. In 2005 the broad lettered, "NORTHAMPTON POLICE" was added underneath the stripes.

The department has marked cruisers, a marked pickup truck, and a Crime Scene Services vehicle. The department also has unmarked vehicles for investigative and administrative use.

Technological advances have enhanced the capabilities of the department's primary response vehicles. In 1999, mobile laptop computer systems were added to the marked cruisers. These enable officers to access the Registry of Motor Vehicles, state and national data bases, as well as the department's own computer system. In 2008, mobile video recorders were added to the primary response marked cruisers. Additionally, interoperable capable, two-way radios, which allow for inter-public safety agency communications in the event of emergencies, are in all department vehicles.

In 2012, Ford discontinued production of the Crown Victoria. As a result, the NPD fleet began a slow transition from the familiar sedans to the Ford Explorer SUVs. These vehicles allow access to areas of the city that we had been unable to consistently patrol in the sedans. They also enhanced our ability to respond to calls in adverse weather conditions.

In 2017, the police department purchased our first hybrid vehicles. Two sedans used for administrative services, including traveling to and from training classes, were purchased. In 2020, Ford first offered a hybrid Ford Explorer police package and two hybrid cruisers were purchased in place of our traditional full fuel models. We hope that one day, our vehicle fleet will be fully hybrid/electric.

In 2023, we added our first fully electric vehicle to the fleet. A Ford Lightning truck was added to the fleet and is used by our Animal Control Officers.