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2009 Edition Chapter 5A. General
Section 5A.01 Function
Standard:
01 A low-volume road shall be defined for this Part of the Manual as follows:
- A low-volume road shall be a facility lying outside of built-up areas of cities, towns, and communities, and it shall have a traffic volume of less than 400 AADT.
- A low-volume road shall not be a freeway, an expressway, an interchange ramp, a freeway service road, a road on a designated State highway system, or a residential street in a neighborhood. In terms of highway classification, it shall be a variation of a conventional road or a special purpose road as defined in Section 1A.13.
- A low-volume road shall be classified as either paved or unpaved.
Support:
02 Low-volume roads typically include agricultural, recreational, resource management and development such as mining and logging and grazing, and local roads in rural areas.
Guidance:
03 The needs of unfamiliar road users for occasional, recreational, and commercial transportation purposes should be considered.
Support:
04 At some locations on low-volume roads, the use of traffic control devices might be needed to provide the road user limited, but essential, information regarding regulation, guidance, and warning.
05 Other Parts of this Manual contain provisions applicable to all low-volume roads; however, Part 5 specifically supplements and references the provisions for traffic control devices commonly used on low-volume roads.
Section 5A.02 Application
Support:
01 It is possible, in many cases, to provide essential information to road users on low-volume roads with a limited number of traffic control devices. The focus might be on devices that:
- Warn of conditions not normally encountered,
- Prohibit unsafe movements, or
- Provide minimal destination guidance.
Standard:
02 The provisions contained in Part 5 shall not prohibit the installation or the full application of traffic control devices on a low-volume road where conditions justify their use.
Guidance:
03 Additional traffic control devices and provisions contained in other Parts of the Manual should be considered for use on low-volume roads.
Support:
04 Section 1A.09 contains information regarding the assistance that is available to jurisdictions that do not have engineers on their staffs who are trained and/or experienced in traffic control devices.
Section 5A.03 Design
Standard:
01 Traffic control devices for use on low-volume roads shall be designed in accordance with the provisions contained in Part 5, and where required, in other applicable Parts of this Manual.
02 The typical sizes for signs and plaques installed on low-volume roads shall be as shown in Table 5A-1. The sizes in the minimum column shall only be used on low-volume roads where the 85th-percentile speed or posted speed limit is less than 35 mph.
| Sign or Plaque | Sign Designation | Section | Sign Sizes | ||
|---|---|---|---|---|---|
| Typical | Minimum | Oversized | |||
| Stop | R1-1 | 5B.02 | 30 x 30 | — | 36 x 36 |
| Yield | R1-2 | 5B.02 | 30 x 30 x 30 | — | 36 x 36 x 36 |
| Speed Limit | R2-1 | 5B.03 | 24 x 30 | 18 x 24 | 36 x 48 |
| Do Not Pass | R4-1 | 5B.04 | 24 x 30 | — | 36 x 48 |
| Pass With Care | R4-2 | 5B.04 | 24 x 30 | 18 x 24 | 36 x 48 |
| Keep Right | R4-7 | 5B.04 | 24 x 30 | 18 x 24 | 36 x 48 |
| Do Not Enter | R5-1 | 5B.04 | 30 x 30 | — | 36 x 36 |
| No Trucks | R5-2 | 5B.04 | 24 x 24 | — | 30 x 30 |
| One Way | R6-2 | 5B.04 | 18 x 24 | — | 24 x 30 |
| No Parking (symbol) | R8-3 | 5B.05 | 24 x 24 | 18 x 18 | 30 x 30 |
| No Parking | R8-3a | 5B.05 | 18 x 24 | — | 24 x 30 |
| No Parking (plaque) | R8-3cP,3dP | 5B.05 | 24 x 18 | 18 x 12 | 30 x 24 |
| Road Closed | R11-2 | 5B.04 | 48 x 30 | — | — |
| Road Closed, Local Traffic Only | R11-3a | 5B.04 | 60 x 30 | — | — |
| Bridge Out, Local Traffic Only | R11-3b | 5B.04 | 60 x 30 | — | — |
| Road Closed to Thru Traffic | R11-4 | 5B.04 | 60 x 30 | — | — |
| Weight Limit | R12-1 | 5B.04 | 24 x 30 | — | 36 x 48 |
| Grade Crossing (Crossbuck) | R15-1 | 5F.02 | 48 x 9 | — | — |
| Number of Tracks (plaque) | R15-2P | 5F.02 | 27 x 18 | — | — |
| Horizontal Alignment | W1-1,2,3,4,5,6 | 5C.02 | 30 x 30 | — | 36 x 36 |
| One-Direction Large Arrow | W1-6 | 5C.02 | 36 x 18 | — | 48 x 24 |
| Two-Direction Large Arrow | W1-7 | 5C.02 | 36 x 18 | — | 48 x 24 |
| Chevron Alignment | W1-8 | 5C.02 | 12 x 18 | — | 18 x 24 |
| Intersection Warning | W2-1,2,3,4,5 | 5C.03 | 30 x 30 | — | 36 x 36 |
| Stop Ahead | W3-1 | 5C.04 | 30 x 30 | — | 36 x 36 |
| Yield Ahead | W3-2 | 5C.04 | 30 x 30 | — | 36 x 36 |
| Be Prepared to Stop | W3-4 | 5G.05 | 36 x 36 | — | 48 x 48 |
| Narrow Bridge | W5-2 | 5C.05 | 30 x 30 | — | 36 x 36 |
| One Lane Bridge | W5-3 | 5C.06 | 30 x 30 | — | 36 x 36 |
| Hill | W7-1 | 5C.07 | 30 x 30 | — | 36 x 36 |
| XX % Grade (plaque) | W7-3P | 5C.07 | 24 x 18 | — | 30 x 24 |
| Next XX Miles (plaque) | W7-3aP | 5C.09 | 24 x 18 | — | 30 x 24 |
| Pavement Ends | W8-3 | 5C.08 | 30 x 30 | — | 36 x 36 |
| Truck Crossing | W8-6 | 5C.09 | 30 x 30 | — | 36 x 36 |
| Loose Gravel | W8-7 | 5G.05 | 30 x 30 | — | 36 x 36 |
| Rough Road | W8-8 | 5G.05 | 30 x 30 | — | 36 x 36 |
| Road May Flood | W8-18 | 5G.05 | 30 x 30 | — | 36 x 36 |
| Grade Crossing Advance Warning | W10-1 | 5F.03 | 30 Dia. | — | 36 Dia. |
| Grade Crossing Advance Warning | W10-2,3,4 | 5F.03 | 30 x 30 | — | 36 x 36 |
| Trains May Exceed 80 mph | W10-8 | 5F.06 | 30 x 30 | — | 36 x 36 |
| Storage Space Symbol | W10-11 | 5F.06 | 30 x 30 | — | 36 x 36 |
| Skewed Crossing | W10-12 | 5F.06 | 30 x 30 | — | 36 x 36 |
| Entering/Crossing | W11 Series | 5C.09 | 30 x 30 | — | 36 x 36 |
| Advisory Speed (plaque) | W13-1P | 5C.10 | 18 x 18 | — | 24 x 24 |
| Dead End/No Outlet | W14-1,2 | 5C.11 | 30 x 30 | — | 36 x 36 |
| Dead End/No Outlet | W14-1a,2a | 5C.11 | 36 x 9 | 24 x 6 | — |
| No Passing Zone (pennant) | W14-3 | 5G.05 | 40 x 40 x 30 | — | 48 x 48 x 36 |
| Supplemental Distance (plaque) | W16-2P | 5C.09 | 24 x 18 | 18 x 12 | 30 x 24 |
| Diagonal Arrow (plaque) | W16-7P | 5C.09 | 24 x 12 | — | 30 x 18 |
| Ahead (plaque) | W16-9P | 5C.09 | 24 x 12 | — | 30 x 18 |
| No Traffic Signs | W18-1 | 5C.12 | 30 x 30 | 24 x 24 | 36 x 36 |
| Road Work (with distance) | W20-1 | 5G.05 | 36 x 36 | — | 48 x 48 |
| Road Closed (with distance) | W20-3 | 5G.05 | 36 x 36 | — | 48 x 48 |
| One Lane Road (with distance) | W20-4 | 5G.05 | 36 x 36 | — | 48 x 48 |
| Flagger | W20-7 | 5G.05 | 36 x 36 | — | 48 x 48 |
| Workers | W21-1 | 5G.05 | 36 x 36 | — | 48 x 48 |
| Fresh Oil | W21-2 | 5G.05 | 30 x 30 | — | 48 x 48 |
| Road Machinery Ahead | W21-3 | 5G.05 | 30 x 30 | — | 48 x 48 |
| Shoulder Work | W21-5 | 5G.05 | 36 x 36 | — | 48 x 48 |
| Survey Crew | W21-6 | 5G.05 | 36 x 36 | — | 48 x 48 |
| Utility Work (with distance) | W21-7 | 5G.05 | 36 x 36 | — | 48 x 48 |
Notes:
- Larger sizes may be used when appropriate
- Dimensions are shown in inches and are shown as width x height
Guidance:
03 The sizes in the oversized column should be used where engineering judgment indicates a need based on high vehicle operating speeds, driver expectancy, traffic operations, or roadway conditions.
Option:
04 Signs and plaques larger than those shown in Table 5A-1 may be used (see Section 2A.11).
Standard:
05 All signs shall be retroreflective or illuminated to show the same shape and similar color both day and night, unless specifically stated otherwise in other applicable Parts of this Manual. The requirements for sign illumination shall not be considered to be satisfied by street, highway, or strobe lighting.
06 All markings shall be visible at night and shall be retroreflective unless ambient illumination provides adequate visibility of the markings.
Section 5A.04 Placement
Standard:
01 Except as provided in Paragraph 3, the traffic control devices used on low-volume roads shall be placed and positioned in accordance with the lateral, longitudinal, and vertical placement provisions contained in Part 2 and other applicable Sections of this Manual.
Guidance:
02 The placement of warning signs should comply with the guidance contained in Section 2C.05 and other applicable Sections of this Manual.
Option:
03 A lateral offset of not less than 2 feet from the roadway edge to the roadside edge of a sign may be used where roadside features such as terrain, shrubbery, and/or trees prevent lateral placement in accordance with Section 2A.19.
Standard:
04 If located within a clear zone, post-mounted sign supports shall be yielding, breakaway, or shielded with a longitudinal barrier or crash cushion as required in Section 2A.19.
