be desirable to monitoring certain conditions over a fixed period of time for example passenger load may be monitored for a month to establish operating conditions and then no longer monitored for this reason it is desirable to have a monitoring system that can be readily and easily modified to meet the needs of a particular vehicle the inventive system and method presented herein fulfills that desire by creating a modular monitoring system that is a monitoring system which is based on removable and interchangeable hardware and software modules the modular monitoring system permits the same system to be installed on multiple vehicles and suitably modified for individual vehicles with minimal time and expense requirements the system as shown in fig2 consists of a core unit 20 which fulfills the purposes of monitoring various conditions through attached and integrated hardware and software modules 30 the core unit 20 is mounted on the vehicle and has a display 22 and or is integrated into existing displays on the dashboard of the vehicle 10 preferably the core unit 20 also has an input device 24 such as a keyboard or keypad to allow for control of the core unit 20 and the modules connected to the core unit 20 the core unit 20 itself may be.