Minimum railing heights must be maintained, even during subsequent bridge maintenance overlays. In order to achieve minimum railing height, the following actions are available: Mill the existing overlay prior to new overlay application; taper the new overlay at a maximum 1 to 10 slope over the width of the shoulder to zero depth at the rail; or both.

If minimum railing height cannot be achieved with milling or tapering the overlay, the railing must be retrofitted to its minimum height when allowed by the criteria in Table 4-1. The Bridge Division is available to assist when details for raising railing heights are required.