Final Answer:
On-the-spot roadside tests that help officers detect impairment from alcohol include field sobriety tests, breathalyzer tests, and preliminary alcohol screening.
Step-by-step explanation:
1. **Field Sobriety Tests:** These are physical and cognitive tests conducted by law enforcement officers to assess a person's coordination, balance, and ability to follow instructions. Common field sobriety tests include the walk-and-turn, one-leg stand, and horizontal gaze nystagmus. These tests help officers observe signs of impairment.
2. **Breathalyzer Tests:** Officers use breathalyzers to measure the alcohol content in a person's breath. The person blows into the device, and it provides a blood alcohol concentration (BAC) reading. This objective measure is crucial in determining if a person is driving under the influence of alcohol.
3. **Preliminary Alcohol Screening (PAS):** PAS devices are handheld breathalyzer instruments used for initial alcohol screening. They provide a quick indication of whether a person has consumed alcohol. While not as precise as evidential breathalyzers, PAS tests are valuable for on-the-spot assessments.
In summary, the on-the-spot roadside tests for detecting alcohol impairment involve a combination of field sobriety tests, breathalyzer tests, and preliminary alcohol screening. These tests equip officers with tools to assess and address potential instances of impaired driving.