What environmental factors can affect performance on SFSTs?

Performance on Standardized Field Sobriety Tests (SFSTs) can be significantly influenced by various environmental factors. Weather conditions such as rain, snow, or wind can create hazardous surfaces that may affect an individual's ability to balance and complete the tests accurately. Lighting conditions can also play a crucial role; for instance, performing tests under bright sunlight or dim lighting can impact visibility and the participant’s overall performance. Additionally, surface stability is critical; uneven or slippery surfaces can lead to missteps, affecting the assessment of sobriety.

In contrast, the other options focus on elements that do not have a direct impact on the physical performance during SFSTs. While traffic volume and road signs may create distractions for a driver, they do not influence the physical capabilities required to complete the tests. Similarly, although time of day may affect an individual’s alertness, it is not a primary environmental factor that directly affects the execution of SFSTs in the same way that weather and surface conditions do.