Work Zone - Appendix F
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Appendix F: Portable Changeable Message Sign Guidelines
Portable Changeable Message Signs (PCMS) are used to provide motorists real-time traffic safety and advance guidance information that allows motorists to make an informed decision when approaching a work zone. This includes scheduled and unscheduled events that significantly impact traffic on the roadways.
Application Guidelines for PCMS
PCMS provide a variety of functions including:
- Ramp, lane, and road closures
- Traffic pattern changes (i.e. temporary crossovers & width restrictions)
- Moving Work Crews
- Roadwork Scheduling Advisories
- Traffic Management and alternate routing
- Warning of Adverse Road Conditions
- Traffic Operations Control
- Real-time Travel Time Messages
- Incident Management
- Safety Messages
PCMS Applications (ranked in order of importance):
Advance Time Notification
- Roadway Closures: Advance notice message, displayed 7-14 days prior to closure, addresses the temporary closure (short duration) of roadways for planned work i.e. truss or bridge beam installations.
- Ramp Closures: Displaying the message 3-7 days prior to the closure is recommended. For freeway to freeway or weekend closures on freeways with high recreational/tourist travel, the message should be displayed longer (up to 14 days), and should include two Thursdays prior to closures. The message should include the start date/time as well as opening of the closure.
- Lane Closures: Same as Ramp Closures.
- Planned Maintenance Work: it is recommended that the message is displayed 714 days prior to the planned work and include the start date/time and estimated completion date.
The message(s) displayed during the closure/work will differ from those displayed prior to the event.
Existing Events
- Detour/Alternate Routes: The message should recommend detours/alternate routes during ramp/lane/roadway closures.
- Notice of Operations: Within unusual roadway geometrics, PCMS devices may be used as an advanced warning device in conjunction with static signing for stationary or moving operations. Hills, curves, and other unusual geometrics obstruct the view of motorists; a PCMS provides an additional notice/warning. Cancelation and completion of roadwork should also be messaged when applicable.
- Work Zone Traffic Backups: Involves monitoring congestion and backups (real- time). This is an ideal use for PCMS and requires a stopped traffic advisory system to be added to the project. Generic traffic backup messages should be avoided as theyis decreases the effectiveness of the stopped traffic advisory system. Programing a message during peak traffic time frames is allowed, but this message should not remain in place during off peak hours.
- Special Event Traffic Conditions: Unusual vehicle and/or non-motorized traffic patterns generated by sporting or charity events are examples for PCMS use. PCMS boards shall not be used under ANY circumstances to advertise special events. Messages for special events should be designed such that advertising is not embedded in the message. The message shall identify traffic conditions and a suggested remedy for those attending the special event and those using the same roadway to pass by the special event location.
- Real-Time, Travel Time Messages: Real-time, travel time messages are recommended to be displayed when other, higher priority messages are not available/needed. This provides useful information on current roadway conditions, providing the motorist with real-time information for informed decision making.
- Incident Management: Post roadway or lane closures due to crashes or incidents which cannot be addressed with static signing only.
- Safety Messages: If used, messages must be pre-approved by the Work Zone Business Team or a common National Work Zone approved message. Safety message should rarely be used on PCMS boards for work zones.
- Traffic Calming: LIMITED USE of messages to inform motorists of closures are permitted. Traffic calming messages indicate the reason a lane is closed (if not obvious) or when a lane will be re-opened. For example, messages notifying of an estimated opening may be displayed during the life of the closure.
Prohibited Use of PCMS
- Replacement of Michigan Manual of Uniform Traffic Control Devices (MMUTCD) required static signing or pavement markings.
- Advertising of any kind.
- No animation or rapid flashing symbols, pictures, or text.
- Lighted arrow replacement. (Exception: May allow static chevrons or a static arrow to provide additional direction on a detour route).
Message Objective
PCMS boards should clearly identify what is happening within the work zone area. It should provide useful, actionable information to the motorist. Vague or generic messaging should not be used.
PCMS boards should clearly state the objective of the message by considering the following:
| Question | Example Message |
|---|---|
| What is ahead? | (LEFT/RIGHT LANE CLOSED AHEAD) |
| How far away? | (XX MILES AHEAD) |
| Where? | (WOODWARD TO MOUND) |
| When? | (STARTS FRIDAY 8AM-9PM) |
| Directions advised? | (FOLLOW DETOUR) |
The message should be designed to display the most important information, in as condensed a manner as possible, to meet the requirements of message timing.
PCMS Messaging Guidance
Drivers must be able to see, read, and comprehend the message on a PCMS. It is essential that messages are clear, concise, and easily comprehended by the general public.
It is also important to properly describe the roadwork or incident location based on the expected audience. The public should believe that PCMS boards contain important, useful, and accurate information, so they read every message, every time. Providing inaccurate, confusing, non-priority messages reduces motorist interest, increasing risk factors, and ultimately leading to a loss of credibility.
PCMS must provide an 18-inch character height, with a maximum eight characters per line and three lines of text. Commuters are typically familiar with street names; however, tourists are not. Route Numbers should be used whenever possible. (Ex. M-24, US-23, I-696). When providing dates, use words for numbers whenever possible, because they are easier to read and comprehend. For example, use the format “NOV 24” instead of “11/24/11”. Also, when possible, use days instead of dates for upcoming construction. “SAT-SUN” is easier to understand than “4/13 – 4/14.”
Full Matrix LED PCMS BOARDS
NTCIP-Compliant, Full-Matrix Portable Changeable Message Boards may be used on projects as approved by each Region. Projects that may warrant the use of these pay items include locations where messages may require more than eight characters per line (with a 10-character maximum), on projects utilizing real-time travel time messages and unique messaging situations as determined appropriate.
Prohibited Messaging
The below messages do not provide the public with any guidance as it relates to an upcoming work zone and should not be used unless they meet the exceptions.
| Prohibited Messaging | Exceptions |
|---|---|
| ONGOING ROAD WORK | None |
| DRIVE WITH CAUTION or EXPECT DELAYS |
Crash, Incident, or Emergency |
| WATCH FOR BACKUPS | Stop Traffic Advisory and Temporary Portable Rumble Strip Projects |
| WORKZONE SPEED LIMIT STRICTLY ENFORCED | Project is patrolled 24/7 |
PCMS Not in Use & Storage
When PCMS is not needed for a message as contained in these guidelines, it must be turned off and removed from the road side, as indicated in the Standard Specifications for Construction. PCMS boards must never be turned sideways and stored on the shoulder or edge of roadway.
If during construction the message board is in an area that has limited access or may be used at a later date in the same location, 4 stars (*) may be placed in a flashing mode, with the first screen having the upper right and lower left stars (*) and the second screen having the lower right upper left stars (*). This notifies the public that the board is working, but no message is being conveyed to them.
PCMS Location
PCMS should be visible from at least 1/2 mile under both daytime and nighttime conditions. Placement in advance of the work zone or incident should take into account the following factors:
- Where used for route diversion, PCMS should be placed far enough in advance to allow traffic ample opportunity to exit the affected roadway.
- PCMS are normally placed on a level shoulder of the roadway, perpendicular to traffic. If practical, placement further from the traveled lane is suggested.
- PCMS boards are typically located in remote locations, not easily accessed and far from a contractor's office. NTCIP PCMS boards are highly recommended for these areas.
- Delineate PCMS as described in the standard specifications.
- PCMS Boards must be locked at all times.
- PCMS Boards should not be located within 1000 ft. of an existing Digital Message Sign Board (DMS).
- PCMS Board locations should be detailed in construction plan sheets. When no plan sheets exist, the boards should be located by TSC staff prior to project startup.
- PCMS boards must be maintained at all times. This includes areas of dirt and dust and during the winter months, ensuring the dimming lens is free of debris, snow, and salt spray.
Temporary Rumble Strip PCMS Placement
PCMS boards may be used in conjunction with temporary rumble strips on a project. The boards should be placed a minimum of 500 ft. after a set of rumble strips to allow the driver time to read and comprehend the message.
Stop Traffic Advisory PCMS Placement
PCMS boards should be placed on both sides of the roadway. Boards should be staggered approximately 1000 ft. apart to ensure the flash rate is not distracting to motorists. Depending upon the determined length of backup and the amount of PCMS boards placed on the project, boards should be placed every 0.5-1.0 mile apart in advance of the lane closure taper.
Message Timing
Sequencing messages are typically used when situations dictate the need for more messages than what can be displayed at one time on a PCMS. The cycle time and duration of the message is related to the operating speed of the highway. All message sequences should consist of a maximum of two messages and with a two-second minimum display time for each message. If additional sequences are needed, a second PCMS should be placed on the same side of the roadway, separated by at least 1000 ft.
Incident Management
Incident management messaging should reference the MDOT Dynamic Message Sign Guidelines. Questions / examples of incident messaging provided below.
| Questions | Example Message |
|---|---|
| What Happened? | (CRASH) |
| Where? | (AT LIVERNOIS) |
| What is the effect? | (LEFT LANE BLOCKED) |
| Who is affected? | (THRU TRAFFIC) |
| What is advised? | (EXPECT DELAYS) |
Abbreviations
Due to limitations of PCMS size or the message length, it is sometimes necessary to abbreviate words. The use of abbreviations however, should be minimized. The following are nationally recognized abbreviations for frequently used words:
Standard Abbreviations
| Word Message |
Standard Abbreviation |
|---|---|
| Afternoon/Evening | PM |
| Alternate | ALT |
| Avenue | AVE, AV |
| Bicycle | BIKE |
| Boulevard | BLVD |
| Cannot | CANT |
| Center | CNTR |
| Circle | CIR |
| Civil Defense | CD |
| Court | CT |
| Crossing (other than highway-rail) |
|
| Do Not | DONT |
| Drive | DR |
| Emergency | EMER |
| Entrance, Enter | ENT |
| Expressway | EXPWY |
| Feet | FT |
| FM Radio | FM |
| Freeway | FWY |
| Friday | FRI |
| Hazardous Material | HAZMAT |
| Highway | HWY |
| Highway-Rail Grade Crossing Pavement Marking |
RXR |
| Hospital | H |
| Hour(s) | HR |
| Information | INFO |
| It is | ITS |
| Junction/Intersection | JCT |
| Lane | LN |
| Left | LFT |
| Maintenance | MAINT |
| Mile(s) | MI |
| Miles Per Hour | MPH |
| Word Message |
Standard Abbreviation |
|---|---|
| Minute(s) | MIN |
| Monday | MON |
| Morning/Late Night | AM |
| Normal | NORM |
| Parking | PKING |
| Parkway | PKWY |
| Pedestrian | PED |
| Place | PL |
| Pounds | LBS |
| Right | RHT |
| Road | RD |
| Saturday | AT |
| Service | SERV |
| Shoulder | SHLDR |
| Slippery | SLIP |
| Speed | SPD |
| Street | ST |
| Sunday | SUN |
| Telephone | PHONE |
| Temporary | TEMP |
| Terrace | TER |
| Thursday | THURS |
| Traffic | TRAF |
| Trail | TR |
| Travelers | TRAVLRS |
| Tuesday | TUES |
| Two-Way Intersection | 2-WAY |
| Two-Wheeled Vehicles | CYCLES |
| US Numbered Route | US |
| Vehicle(s) | VEH |
| Warning | WARN |
| Wednesday | WED |
| Will Not | WONT |
Abbreviations Used with Prompts
Other abbreviations are easily understood when they appear with a prompt word commonly associated with it. The prompt word must be spelled out when used with the abbreviated word.
| Word | Abbreviation | Prompt Word |
|---|---|---|
| Access | ACCS | Road |
| Ahead | AHD | Fog* |
| Blocked | BLKD | Lane* |
| Bridge | BRDG | (Name)* |
| Chemical | CHEM | Spill |
| Condition | COND | Traffic* |
| Congested | CONG | Traffic* |
| Construction | CONST | Ahead |
| Downtown | DWNTN | Traffic |
| Exit | EXT | Next* |
| Express | EXP | Lane |
| Frontage | FRNTG | Road |
| Hazardous | HAZ | Driving |
| Interstate | I | (Number) |
| Local | LOC | Traffic |
| Major | MAJ | Accident |
| Minor | MNR | Accident |
| Minute(s) | MIN | (Number)* |
| Oversized | OVRSZ | Load |
| Pavement | PVMT | Wet* |
| Prepare | PREP | To Stop |
| Quality | QLTY | Air* |
| Roadwork | RDWK | Ahead (Distance) |
| Route | RT, RTE | Best* |
| Township | TWNSHP | Limits |
| Turnpike | TRNPK | (Name)* |
| Cardinal Directions | NB, EB, SB, WB | (Number) |
| Upper, Lower | UPR, LWR | Level |
| Work | WRK | Road* |
Abbreviations should be used cautiously with prompt words as they can cause confusion when used in the wrong context. For example, drivers interpret BLKD as BLOCKED when it appears with LANE in the form LANE BLKD. CHEM is interpreted by drivers as CHEMICAL when used in the message as CHEM SPILL. The table below provides a list of abbreviations that are easily misinterpreted.
Unacceptable Abbreviations
| Abbreviation | Header Intended Word | Common Misinterpretations |
|---|---|---|
| ACC | Accident | Access (Road) |
| CLRS | Clears | Colors |
| DLY | Delay | Daily |
| FDR | Feeder | Federal |
| L | Left | Lane (Merge) |
| LT | Light (Traffic) | Left |
| PARK | Parking | Park |
| POLL | Pollution (Index) | Poll |
| RED | Reduce | Red |
| STAD | Stadium | Standard |
| WRNG | Warning | Wrong |
Sample Messaging
Standard Messages
| RIGHT(LEFT) LANE CLOSED | XX MILES AHEAD |
| TRAFFIC SHIFT RIGHT(LEFT) | XX MILES AHEAD |
| RD WORK US-24 TO M-39 | RIGHT(LEFT) LN CLOSED AHEAD |
| NEW TRAFFIC PATTERN | XX MILES AHEAD |
| ROAD WORK AHEAD | 8 MILE TO 9 MILE |
| RD WORK US-24 TO ECORSE | TRUCKS USE LEFT(RIGHT) LANE |
| NARROW LANES AHEAD | REDUCE SPEED |
| NARROW LANES AHEAD | OVERSIZE LOADS EXIT XXX |
| RD WORK AT LAPEER | STARTING APRIL 5TH |
| RD WORK M-24 TO M-15 | BEGINS APRIL 5TH |
| NIGHTLY LANE CLOSURES | 9PM TO 5AM |
Stop Traffic Advisory System
| SLOW TRAFFIC AHEAD | WATCH FOR BACKUPS |
| STOPPED TRAFFIC AHEAD | BE PREPARED TO STOP |
| SLOWED TRAFFIC | XX MILES AHEAD |
| STOPPED TRAFFIC | XX MILES AHEAD |
| RD WORK XX MILES AHEAD | TRUCKS USE LEFT(RIGHT) LANE |
| RD WORK US-24 TO M-39 | MOTRCYCLS USE LEFT(RIGHT) LANE |
Rumble Strips
| RUMBLE STRIPS AHEAD | ATTENTION MOTOR-CYCLES |
| RUMBLE STRIPS | XX MILES AHEAD |
| RUMBLE STRIPS AHEAD | REDUCE SPEED |
Detours
| HAMBURG ROAD CLOSED | FOLLOW DETOUR |
| HAMBURG ROAD CLOSED | USE EXIT XXX |
| WB I-94 TRAFFIC | USE 8 MILE RD |
| WB I-94 CLOSED | FOLLOW DETOUR |
| US-24 RAMP CLOSED | USE EXIT XXX |
| US-24 RAMP CLOSED | FOLLOW DETOUR |
Freeway Stoppages
| 15 MIN CLOSURES | STARTING MON 9PM TO 5AM |
| 15 MIN FWY CLOSURES | SEEK ALT ROUTE |
| NIGHTLY FWY CLOSURES | MON-FRI 9PM TO 5AM |
