Technical Abstract: Data from soil ground pressure sensors show that residual stress, or the net stress remaining after a vehicle has passed over the sensor, is proportional to peak stress or peak compaction force. This suggests a simple way to measure and compare soil compaction between different vehicles or treatments. This paper reviews two methods of measuring peak and residual soil stress, comparing results from a simple method to results from a more rigorous method, and reports the magnitude of the measured residual stress, and the relationships between residual stress, vehicle ground pressure and soil compactibility. Favorable results were obtained when comparing these residual pressures versus the maximum soil pressures. Differences were also measured between various tire inflation pressures, tire loads, sensor depth, and between tires and tracks. Favorable comparisons were also made between this simple pressure bulb sensor and a more complex electronic sensor used to measure the entire soil stress state. Because of this research, producers may be able to use these simple pressure bulbs to predict when their fields are compactable and avoid trafficking them.