Parallel-mounted On-premise Letter Height and Sign Size

Research and common sense attest to the fact that on-premise projecting signs are more detectable and are readable further away and at smaller sizes than wall-mounted signs. The objective of the current study was to conduct a small-scale field validation of earlier research on minimum letter heights for wall signs and to provide associated minimum square footage for these signs. Eight wall signs that varied in letter height and lateral offset were identified for evaluation on two roadways that varied in posted speed limit and cross-section in Nags Head, North Carolina. Using an empirical procedure involving driving and walking toward the signs, the legibility distances for these signs were evaluated and were found to compare favorably to past research that employed an analytical approach. An equation to determine sign size in square feet was also developed. Future research to further these findings is outlined.