Safe Highway Markings Act of 2010 - Prescribes minimum standards for engineered glass beads used in reflective markings, limiting the arsenic content to 200 parts per million.
Requires states that receive certain federal-aid highway funds to ensure that any new application of reflective markings on or along federal-aid highway roads or highways be made from a binder that has been mixed, in whole or in part, with engineered glass beads.
Requires the Secretary of Transportation, acting through the Administrator of the Federal Highway Administration (FHWA), to withhold up to 5% of the apportionment of funds for any state that does not comply with such standards.