Abstract: A magnetometer vehicle detector for detecting various parameters of traffic on a roadway. A number of sensors, having a compact package, along with connecting cables, may be placed in road way with a small number of standard width sawcuts. Alternatively, sensors may be placed in the roadway within tubes under the external surface of the roadway. The package design of the sensor is such that the sensor can be placed in the sawcut or tube only in a certain way or ways resulting in the most sensitive axis of the sensor being most likely affected by just the traffic or vehicles desired to be detected and measured. The sensor may be a magnetoresistive device having a permalloy magnetic sensing bridge. Multiple sensors may be placed in single or multiple lanes of the roadway for noting the presence of vehicles and measuring traffic parameters such as average speeds, vehicle spacings, and types and numbers of vehicles.