A traffic signal warrant study can determine the need for installation through all of the following except:

A traffic signal warrant study is a systematic approach used to decide whether a traffic signal should be installed at a specific location. The study typically analyzes several factors such as traffic volumes, pedestrian activity, and safety data.

The rationale behind the choice being correct is that while local requests for installation can highlight community concerns or desires, they do not inherently provide the necessary quantitative evidence required by warrant studies. The study should base its determination on factual data regarding traffic conditions and safety rather than subjective requests or local pressures.

In contrast, traffic volumes indicating insufficient gaps on the major street, pedestrian volumes indicating a need for safe crossing, and historical crash data are all quantitative measures that can provide objective insights into the traffic conditions. Each of these elements meets warrant criteria established by guidelines such as those from the Manual on Uniform Traffic Control Devices (MUTCD), which focuses on ensuring that signals are installed where they are genuinely needed for safety and efficiency reasons. Thus, local requests alone do not fulfill the comprehensive assessment that warrant studies are designed to conduct.