Delaware Administrative Code
Title 2 - Transportation
2000 - Department of Transportation
2400 - Division of Transportation Solutions
2402 - Manual on Uniform Traffic Control Devices (MUTCD)
Part 6 - Temporary Traffic Control
Chapter 6F - TEMPORARY TRAFFIC CONTROL ZONE DEVICES
Section 6F.60 - Portable Changeable Message Signs
Current through Register Vol. 28, No. 3, September 1, 2024
Support:
01 Portable changeable message signs (PCMS) are TTC devices installed for temporary use with the flexibility to display a variety of messages. In most cases, portable changeable message signs follow the same provisions for design and application as those given for changeable message signs in Chapter 2L. The information in this Section describes situations where the provisions for portable changeable message signs differ from those given in Chapter 2L.
02 Portable changeable message signs are used most frequently on high-density urban freeways, but have applications on all types of highways where highway alignment, road user routing problems, or other pertinent conditions require advance warning and information.
03 Portable changeable message signs have a wide variety of applications in TTC zones including: roadway, lane, or ramp closures; incident management; width restriction information; speed control or reductions; advisories on work scheduling; road user management and diversion; warning of adverse conditions or special events; and other operational control.
04 The primary purpose of portable changeable message signs in TTC zones is to advise the road user of unexpected situations. Portable changeable message signs are particularly useful as they are capable of:
05 Some typical applications include the following:
Guidance:
06 The components of a portable changeable message sign should include: a message sign, control systems, a power source, and mounting and transporting equipment. The front face of the sign should be covered with a protective material.
Standard:
07 Portable changeable message signs shall comply with the applicable design and application principles established in Chapter 2A. Portable changeable message signs shall display only traffic operational, regulatory, warning, and guidance information, and shall not be used for advertising messages.
Support:
08 Section 2L.02 contains information regarding overly simplistic or vague messages that is also applicable to portable changeable message signs.
Standard:
09 The colors used for legends on portable changeable message signs shall comply with those shown in Table 2A-5.
Support:
10 Section 2L.04 contains information regarding the luminance, luminance contrast, and contrast orientation that is also applicable to portable changeable message signs.
Guidance:
11 Portable changeable message signs should be visible from 1/2 mile under both day and night conditions.
Support:
12 Section 2B.13 contains information regarding the design of portable changeable message signs that are used to display speed limits that change based on operational conditions, or are used to display the speed at which approaching drivers are traveling.
Guidance:
13 A portable changeable message sign should be limited to three lines of eight characters per line or should consist of a full matrix display.
14 Except as provided in Paragraph 15, the letter height used for portable changeable message sign messages should be a minimum of 18 inches.
Option:
15 For portable changeable message signs mounted on service patrol trucks or other incident response vehicles, a letter height as short as 10 inches may be used. Shorter letter sizes may also be used on a portable changeable message sign used on low speed facilities provided that the message is legible from at least 650 feet.
16 The portable changeable message sign may vary in size.
Guidance:
17 Messages on a portable changeable message sign should consist of no more than two phases, and a phase should consist of no more than three lines of text. Each phase should be capable of being understood by itself, regardless of the order in which it is read. Messages should be centered within each line of legend. If more than one portable changeable message sign is simultaneously legible to road users, then only one of the signs should display a sequential message at any given time.
Support:
18 Road users have difficulties in reading messages displayed in more than two phases on a typical three-line portable changeable message sign.
Standard:
19 Techniques of message display such as animation, rapid flashing, dissolving, exploding, scrolling, travelling horizontally or vertically across the face of the sign, or other dynamic elements shall not be used.
Guidance:
20 When a message is divided into two phases, the display time for each phase should be at least 2 seconds, and the sum of the display times for both of the phases should be a maximum of 8 seconds.
21 All messages should be designed with consideration given to the principles provided in this Section and also taking into account the following:
Standard:
22 When the word messages shown in Tables 1A-1 or 1A-2 need to be abbreviated on a portable changeable message sign, the provisions described in Section 1A.15 shall be followed.
23 In order to maintain legibility, portable changeable message signs shall automatically adjust their brightness under varying light conditions.
24 The control system shall include a display screen upon which messages can be reviewed before being displayed on the message sign. The control system shall be capable of maintaining memory when power is unavailable.
25 Portable changeable message signs shall be equipped with a power source and a battery back-up to provide continuous operation when failure of the primary power source occurs.
26 The mounting of portable changeable message signs on a trailer, a large truck, or a service patrol truck shall be such that the bottom of the message sign shall be a minimum of 7 feet above the roadway in urban areas and 5 feet above the roadway in rural areas when it is in the operating mode.
Guidance:
27 Portable changeable message signs should be used as a supplement to and not as a substitute for conventional signs and pavement markings.
28 When portable changeable message signs are used for route diversion, they should be placed far enough in advance of the diversion to allow road users ample opportunity to perform necessary lane changes, to adjust their speed, or to exit the affected highway.
29 Portable changeable message signs should be sited and aligned to provide maximum legibility and to allow time for road users to respond appropriately to the portable changeable Message sign message.
30 (DE Revision) Portable changeable message signs should be placed off the shoulder of the roadway and behind a traffic barrier, if practical. Where a traffic barrier is not available to shield the portable changeable message sign, it should be placed off the shoulder and outside of the clear zone.
Standard:
Guidance:
31 When portable changeable message signs are used in TTC zones, they should display only TTC messages.
32 (DE Revision) Portable changeable message signs should be located, to the extent possible, outside of the clear zone or shielded behind a traffic barrier.
Standard:
Guidance:
33 Portable changeable message sign trailers should be delineated on a permanent basis by affixing retroreflective material, known as conspicuity material, in a continuous line on the face of the trailer as seen by oncoming road users.