104.19 Portable Variable Message Signs (Pvms)
raising and lowering of the sign panel, during sustained wind speeds of 85 mph. The display windows shall be made of impact-resistant clear Lexan or as approved. Sign Panel. Not to exceed 144 in. length, 90 in. height, 12 in. depth. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS CATEGORY 100 PRELIMINARY SECTION 104.19 — PORTABLE VARIABLE MESSAGE SIGNS (PVMS)
104.19.01 Description
Furnish, install and relocate portable, self-contained, trailer mounted variable message signs.
104.19.02 Materials
PVMS QPL All materials shall be like new, corrosion resistant, and unaffected by water spray, salt, oil, gasoline, and all other contaminants in the quantities normally found along the edge of the traveled roadway. Construction, materials, and operation shall meet NFPA, UL, and NEC. Ensure that sign messages are visible and legible for a distance of 900 ft from any point along the traveled approach roadway at all times. The PVMS shall be equipped with a sighting device to provide alignment for maximum visibility.
104.19.03 Construction
104.19.03 01 Equipment.
Trailer. In accordance with Maryland Motor Vehicle Law. Structural Support. The structural support framework shall allow the system to be assembled into a unit and be mounted on the trailer and shall provide the support mechanism between the sign panel assembly, the power supply, and the controller. The framework shall provide sufficient support to prevent damage to any unit component when the sign is in down and locked position during normal highway travel. The deployed structure shall supply adequate support to allow complete sign operation, including
104.19 Portable Variable Message Signs (Pvms)
Display.
a.Capable of displaying three lines of text.
b.Each line of text shall be constructed using either a discrete matrix or a full matrix display.
c.Capable of displaying eight characters per line. (d) The character height shall be at least 18 in. (e) If discrete matrix display is used, each character shall be displayed using a 5 x 7 array with at least eight array modules per line. A 4-1/4 in. to 7 in. space shall exist between each display line with no glare reflection.
f.If full matrix display is used, the sign shall have at least 25 rows and 45 columns of disks. Each display line shall have at least 7 rows and 45 columns of disks and a 4- 1/4 in. to 7 in. space between each display line with no glare reflection. Flip Disk Mechanism.
a.Be electromagnetically activated, with a service life of at least 200 million operations.
b.Have a reflective surface that will maintain color intensity for at least three years. (c) Be circular or rectangular, with a visible surface area between 3-3/4 in
2.and 4-1/4 in2. LED Illumination. LED illumination for each matrix element shall:
a.Meet ITE specification for amber color. (b) Utilize AlInGaP substrate. (c) Each LED shall produce at least a 1 candela output on center at 25 mA drive current. (d) Each matrix element shall have at least two LED's located within the perimeter of the flipping disk.
e.Provide full illumination within at least a 24 degree cone perpendicular to the sign face. (f) Have an operating temperature range of -40 F to 160 F. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
104.19 Portable Variable Message Signs (Pvms)
PVMS UNIT. Lift Mechanism. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
a.Electric or electrically assisted hydraulic mechanism capable of raising and lowering the sign panel.
b.Capable of being raised or lowered manually. (c) Furnished with a stainless steel safety bolt to prevent the sign panel from lowering once in the raised position. A self-locking mechanism shall be incorporated into the safety bolt to prevent it from being inadvertently dislodged.
d.Designed to allow the raised sign panel to rotate 360 degrees about the vertical axis.
1.Allow rotation clockwise and counter-clockwise.
2.A mechanism shall be provided to lock the sign panel in place, at any position. Electrical Connections and Gauges.
a.All wiring from power sources to PVMS equipment shall use locking cable connectors. (b) Volt and amp gauges shall be provided for both AC and DC. (c) Standard negative ground system shall be tied to the sign chassis. (d) Lightning protection shall be supplied to the load side of the sign system's distributed power lines to withstand multiple surges in excess of 600 volts. Power Supply. Either a solar powered electrical system, or existing commercial electrical service. Solar Powered Electrical System. Battery power system and solar array panels capable of displaying a two page message for 21 consecutive days without auxiliary charge. Sign Controller.
a.Capable of driving the matrix display panel operating over a -50 F to 150 F range and in a 20 percent to 100 percent noncondensing humidity range.
b.Accommodate 100 preprogrammed, user-defined messages. (c) Capable of displaying three sequenced messages. On/Off time for each message in a sequence shall be user adjustable within a range of 0 seconds to 5 seconds.
104.19 Portable Variable Message Signs (Pvms)
d.Designed for fail-safe prevention of improper information display in the case of a system malfunction.
e.Cause a user defined default message to be displayed in case of failure of the PVMS unit when flip disk mechanism is used.
f.Have the capability of retrieving all messages stored in temporary memory.
1.Temporary memory shall be nonvolatile.
2.All messages and programs shall remain resident in the controller's memory in the event of a power failure.
3.Have an RS-232 port to facilitate connection of an external communication device.
g.Capable of automatic system recovery after power outages to the central controller without operator intervention, including the ability to maintain an up-to-date status on a remote unit if sign is operated from a remote location.
h.Monitor and display the battery output voltage and solar array activities (charging/discharging) and blank the sign when the battery output voltage drops below the manufacturer's recommended output level.
i.Capable of monitoring and displaying the status of the photocell and adjusting the sign illumination to match the ambient light conditions. The controller shall have at least nine levels of dimming from 10 percent to 100 percent brightness.
j.Contained in a secure weatherproof cabinet located on the controller housing and insulated to protect against excessive vibration, temperature or tampering.
1.Equipped with a lockable door latch and an interior cabinet dome light.
2.Provided with a keyboard storage location inside the cabinet. (3) Security locks shall include those installed by the manufacturer and an additional hardened hasp/lock combination with a user changeable combination. This hasp/lock setup shall be installed in a manner to maximize its effectiveness in stopping unauthorized access to the sign controls. For control box surfaces not compatible with the hasp/lock setup, other supplemental high security locking devices may be approved by the Engineer. Security.
a.Lock all trailer control cabinets when not attended by Administration employee or contractors, whether being stored, in transport, or deployed and activated. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
104.19 Portable Variable Message Signs (Pvms)
highway alignment or glare from either sunlight or vehicle headlights. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
b.Do not store or maintain any passwords on the PVMS.
c.Remove any password attached or inscribed on the PVMS trailer or equipment. (d) Change the password when it is no longer secure, or every 6 months, whichever comes first.
e.Some older model PVMS may not have a changeable password, so extra measures shall be taken to hide the password.
f.Do not leave Owner/Instruction manuals in the trailer control cabinets. Manuals should be copied and made available to the personnel responsible for deploying the PVMS Signs.
g.When equipped with a detachable keyboard, remove it from the trailer and secure in the transport vehicle, field office, or at the respective shop.
h.Failure to comply with these security standards or any subsequent PVMS tampering incidents will be cause for penalty under TC-4.02.
i.Construction and District Inspectors will ensure contractor compliance. Character Set Software.
a.Have all of the standard ASCII characters and symbols.
b.Provide left and right arrows. (c) Have all alphanumeric entries performed with a keyboard or keypad that causes the same character to be displayed on the matrix. Arrow symbols shall be generated via a cursor pad on the keyboard or keypad.
d.Have messages default to self-centering display with the ability to left or right justify a display when full matrix is used.
104.19.03 02 Set up and operate the PVMS on the project site 24 hours in advance of actual use.
Ensure that each unit is functioning properly and approved. Locate the PVMS as specified. Aim the PVMS at approaching traffic in accordance with the 900 ft minimum visibility and legibility requirement. Ensure that the PVMS is level and that the sign face is not obscured by
104.19 Portable Variable Message Signs (Pvms)
tools and incidentals necessary to complete the work. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
104.19.04 Measurement and Payment
Portable Variable Message Sign will be measured and paid for at the Contract price per unit day. A unit day will consist of any approved usage within a work shift, regardless of start time or whether the shift runs into another calendar day. Each portable variable message sign will be paid for only once per unit day, regardless of how many times it may be relocated. When a portable variable message sign is used for part of a day, it will be measured and paid for as a unit day. When operations require continuous 24 hour use of a portable variable message sign, the unit day will be measured as 24 hour periods from start to finish. The payment will be full compensation for the electrical power and hook up, setup and maintenance of computer programs, changing messages, and for all material, labor, equipment,
104.20 Temporary Orange Construction Fence
CATEGORY 100 PRELIMINARY SECTION 104.20 — TEMPORARY ORANGE CONSTRUCTION FENCE
104.20.01 Description
Furnish, install, and maintain new or like new temporary orange mesh construction fence. This fence is not to be used as a safety barrier.
104.20.02 Materials
Precast Concrete Blocks 903.05 Tie Wire, Tension Wires, Tension Wire Clips and Hardware 914.02 Orange Mesh Fencing As approved Fence posts shall be 4 ft high, 1.90 in. diameter round posts; or 5-1/2 ft high, 2 in. steel U channel posts, as specified herein. Submit samples of the fence fabric, fence posts, movable precast concrete blocks, tie wire, tension wires, and other miscellaneous hardware for approval.
104.20.03 Construction
Temporary orange construction fence shall be at least 4 ft high and with a maximum post spacing of 8 ft. When installed on a paved surface, support the fence by inserting the round post into a precast concrete block having a round hole through the center of the block. When installed in unpaved areas, use steel U channel fence posts driven 1-1/2 ft into the ground. Installation of the fence in any other manner will require approval. Secure the fabric to the posts by wrapping a tie wire around the horizontal fence strands and the posts. Install a top tension wire to prevent sagging. When installed on paved surfaces, the Engineer will determine if a bottom tension wire is required. Remove the fence when the Engineer determines that the fence is no longer required. The removed fence is the property of the Contractor. Damaged Construction Fence. Repair or replace damaged construction fence within four hours after notification. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
Source: Maryland Standard Specifications for Construction and Materials, 2025 Edition. Pages 191–196 of 1,113.