TxDOT has used ceramic buttons extensively over the years. Until the recent change to TxDOT’s

Signs and Markings Manual

, which strongly discouraged the use of buttons, they were the third most often used pavement marking material in Texas behind thermoplastic and paint. While buttons often last for at least 2 years under the heaviest traffic conditions on concrete, the major complaint against their use is the lack of retroreflectivity provided by the materials rendering them nearly invisible under headlamp conditions on unlit roadways. While retroreflective raised pavement markings (RRPMs) are always used with buttons to supplement the lack of retroreflectivity, RRPMs generally have short service lives making for poor nighttime visibility conditions when the RRPMs fail. Buttons do provide a tactile and audible sensation when driven over, similar to that of rumble strips, which may be considered a safety benefit.

Ceramic buttons are very different in appearance and application from all other marking materials. If used, they must be supplemented by RRPMs to provide nighttime visibility. Due to the fact that they are a non-retroreflective material, they are somewhat unpopular as a pavement marking material. The availability of application equipment and labor, especially in Texas, makes them an attractive material choice, although they are comparatively expensive. Table 2-16 shows recommendations pertaining to the use of ceramic button pavement markings on concrete.