§ 24.50.003. Barricade application.

A.

On construction projects, when a road section is closed to traffic, type III barricades shall be erected at the points of closure. They may extend completely across a roadway and its shoulders (as a fence) or from curb to curb. Where provision must be made for access of equipment and authorized vehicles, the type III barricades should be provided with gates or movable sections that can be closed when work is not in progress, or with indirect openings that will discourage public entry. Where access is provided through the type III barricades, responsibility should be assigned to a person to assure proper closure at the end of each working day.

B.

When a road or street is legally closed, but access must still be allowed for local traffic, the type III barricade cannot be erected completely across a roadway. Instead, an arrangement should be devised that will permit local use but effectively discourage use by through traffic. A sign with the appropriate legend concerning permissible use by local traffic should be installed.

C.

Applications of this principle are illustrated in figures 6-3 and 6-4.

D.

Type I or type II barricades shall be used when traffic is maintained through the area being constructed and/or reconstructed. The important characteristic of these barricades is that each is movable, and they may be used interchangeably. In general, type I barricades are the heavier and more bulky of the two, but these factors are dependent, in large part, on the materials from which each type is constructed.

E.

The ultimate choice in a given situation would probably be dependent upon the degree of mobility required in the particular project. It should be kept in mind, however, that type I and type II barricades, although movable, are somewhat clumsy and are not as adaptable to changeable situations as traffic cones.

F.

Where maintenance activities are being performed, a street or highway condition is seldom of a character that will require a complete closing of the facility. When such a condition does occur, it is almost always an emergency situation, as would result from a broken water main or a washed-out culvert, for example. Repair work is generally initiated on an emergency basis, and the street or road closing generally is of a kind wherein type I or type II is utilized.

G.

Wing barricades are a special application of type III barricades, erected on the roadway shoulder (on one or both sides of the pavement) to give the illusion of a narrowed or restricted roadway. In advance of a construction or maintenance area, even where no part of the roadway is actually closed, wing barricades serve a useful purpose in alerting the driver. If used in a series, they should start at the outer edge of the shoulder and be brought progressively closer to the pavement. Wing barricades may be used as a mounting for the advance warning or guide signs or lighting devices. During periods of inactivity, a foldaway type of design may be advantageous. Examples of wing barricades are shown in figure 6-11.

H.

Signs may be erected on barricades, particularly those of the fixed type, and they offer a most advantageous facility for this purpose. The road closed and detour arrow signs, and the large arrow warning signs, for example, can effectively be mounted above the barricade that closes the roadway.

(AO No. 80-79)

Authority— Anchorage Municipal Code 3.40, 24.50.040.

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TABLE VI-1. BARRICADES—CHARACTERISTICS

	Type
	I	II	III
Width of rail	3″ minimum—12″ maximum	8″ minimum—12″ maximum	8″ minimum—12″ maximum
Length of rail	6′—8′	3′ minimum—4′ maximum	3′ minimum—variable maximum
Width of stripes	6″	6″	6″
Height	3′ minimum	3′ minimum	5′ minimum
Type of frame	Demountable or heavy A-frame	Light A-frame	Post or skids
Flexibility	Essentially movable	Portable	Essentially permanent

 

FIGURE 6-3. TYPICAL APPLICATION—ROADWAY CLOSED BEYOND DETOUR POINT

ADD FIGURE page 24.50-6

FIGURE 6-4. TYPICAL APPLICATION—DETOUR SIGNING FOR STREET CONSTRUCTION PROJECT IN A STREET GRID

ADD FIGURE page 24.50-8

FIGURE 6-11. METHODS OF MOUNTING SIGNS OTHER THAN ON POSTS

ADD FIGURE page 24.50-8

FIGURE 6-14. STANDARD BARRICADES

ADD FIGURE page 24.50-9