104.22 Automated Flagger Assistance Device (Afad)
CATEGORY 100 PRELIMINARY SECTION 104.22 — AUTOMATED FLAGGER ASSISTANCE DEVICE (AFAD)
104.22.01 Description
An automated flagger assistance device (AFAD) is designed for remote operation by a certified flagger. AFADs shall only be used in situations where there is only one lane of approaching traffic in the direction to be controlled. The AFAD shall be either Type I ‘STOP/SLOW’ Sign system or Type II ‘Red/Yellow’ Lens system. Furnish, install, and maintain a portable, self-contained, AFAD for temporary traffic control as specified in the Contract Documents or as directed. The AFAD shall be crashworthy as specified in Section 104. Furnish certified flagger(s) per 104.15.01 to operate the AFAD(s). Install AFAD related signs and channelizing devices as specified in the Book of Standards for Highways and Incidental Structures.
104.22.02 Materials
AFAD Cones for Maintenance of Traffic Reflectorization Sign Material QPL
104.14 02
950.03 950.08 The AFAD shall be capable of being operated from the controller cabinet mounted on the unit. The unit shall have the ability for manual override in case of remote failure.
104.22.02 01 General System Requirements.
a.Gate Arm. The AFAD shall include a gate arm that is at least 6 ft long and the end of the arm shall reach at least to the center of the lane being controlled. The gate arm shall not extend in the opposite lane. The arm shall have vertical alternating red and white stripes on both sides at 16 in. intervals measured horizontally. The arm shall be made of lightweight rigid material. A retroreflective red or retroreflective fluorescent orange/red flag (minimum of 18 in. square) shall be attached on the end of the roadside end.
b.Remote Control. The AFAD shall be equipped with a weatherproof handheld remote control that is capable of displaying the status of the AFAD display. The remote control 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
104.22 Automated Flagger Assistance Device (Afad)
shall be programmable to control either one unit or two units and be able to control units over the required range.
c.Power Supply. The AFAD shall be able to operate from a solar powered electrical system and consist of battery power and solar array panels.
d.Trailer. The trailer shall be painted orange and shall comply with Maryland Motor Vehicle Law.
104.22.02 02 Type I ‘STOP/SLOW’ Sign AFAD Requirements.
a.‘STOP/SLOW’ Sign. Type I AFAD unit shall include a ‘STOP/SLOW’ sign that alternately displays the STOP (R1-1) face and the SLOW (W20-8) face of a ‘Stop/Slow’ paddle. The ‘STOP/SLOW’ sign shall have an octagonal shape and shall be fabricated of rigid material. The size of the ‘STOP/SLOW’ sign shall be at least 30 in. x 30 in. with letters at least 8 in. high. The background of the STOP face shall be red with white letters and a border. The slow face shall be diamond shaped with fluorescent orange background and black letters and a border. Both faces of the ‘STOP/SLOW’ sign shall be reflectorized as specified in 950.03. The bottom of the ‘STOP/SLOW’ sign shall be mounted a minimum of 7 ft above the pavement.
b.AFAD Related Signs. Type I AFAD shall be supplemented by stationary sign(s) with one of the following options:
1.Separate ‘WAIT ON STOP’ (R1-7) and ‘GO ON SLOW’ (R1-8) signs attached side by side below the STOP/SLOW sign. Each sign shall be 24 in. x 30 in. The background of the sign shall be white with black letters and border, and the sign face shall be reflectorized as specified in 950.03.
2.One combined sign with combined message ‘WAIT ON STOP GO ON SLOW’ attached below the ‘STOP/SLOW’ sign. The sign shall be 36 in. x 36 in. The background of the sign shall be white with black letters and border, and the sign face shall be reflectorized as specified in 950.03. The signs (‘WAIT ON STOP’, ‘GO ON SLOW’, or the combined ‘WAIT ON STOP GO ON SLOW’) shall be positioned on the same support structure as the AFAD such that they are in the same direct line of view of approaching traffic as the sign faces of the AFAD.
c.Conspicuity Devices. The Type I AFAD shall be supplemented with active conspicuity devices. Each AFAD unit shall include a red Stop Beacon mounted a maximum of 24 in. above the ‘STOP/SLOW’ face and yellow warning lights mounted to the side or above the ‘STOP/SLOW’ face. The Stop Beacon shall consist of a 12 in. red LED signal head with a visor and shall steadily illuminate in circular red only during the STOP sign display. The Warning Lights shall illuminate in flashing yellow during the SLOW sign display. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
104.22 Automated Flagger Assistance Device (Afad)
104.22.02 03 Type II ‘Red/Yellow’ Lens AFAD Requirements.
a.Signal Head. Type II AFAD unit shall have a signal head with one set of circular red and circular yellow lenses. The circular red shall be placed on top and the circular yellow below. The signal head shall be as specified in 950.15 and shall meet the physical display and operational requirements of conventional traffic signals according to Part IV of the MdMUTCD. The signal head shall be aluminum or polycarbonate and have two, 12 in. LED indications. The signal head shall be equipped with a visors which extend beyond the signal head a minimum of 10 in. All signal housings shall be black or yellow. The signal head shall have the ability to accommodate a back plate. The lower signal head shall be mounted at a minimum height of 7 ft measured from the bottom of the yellow indication to the road surface.
b.AFAD Related Sign. Type II AFAD shall be supplemented by stationary 24 in. x 36 in. ‘STOP HERE ON RED’ sign (R10-6 or R10-6a). The sign shall have a white background with black letters and border, and the sign face shall be reflectorized as specified in 950.03. The sign shall be installed per MD 104.01-17 on the right-hand side in advance of the unit at the point at which drivers are expected to stop when the steady circular red lens is illuminated.
104.22.03 Construction
104.22.03 01 AFAD. Place the AFAD unit as shown in the Contract Documents or as directed,
with all signs and traffic control devices visible to the driver of the initial approaching vehicle. Install advance warning signs and install cones along the road center line and around the AFAD according to the Book of Standards and the Contract Documents. Ensure that the AFAD is operational for the duration of the lane closure. The AFAD 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 be according to NFPA, ULI, and NEC. When used at night, the AFAD location shall be adequately illuminated.
104.22.03 02 Operation.
a.Type I ‘STOP/SLOW’ Sign AFAD. SLOW to STOP transition. The red Stop Beacon shall enter a ‘flashing mode’ approximately 2 seconds before transitioning from the SLOW face to the STOP face. When the AFAD unit displays the STOP face, the red Stop Beacon shall illuminate in steady red, and the gate arm shall begin descent to the down position 2 seconds after the beacon has displayed the solid red light. STOP to SLOW transition. The gate arm shall begin to ascend to the upright position as the face changes from STOP to SLOW and the red stop light shall cease to illuminate. The yellow beacon(s) shall enter flashing mode. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
104.22 Automated Flagger Assistance Device (Afad)
b.Type II ‘Red/Yellow’ Lens AFAD. To stop road users. The AFAD shall display a steadily illuminated circular red lens and with the gate arm in the down position. To transition to circular red, the flashing circular yellow lens shall enter into 3 seconds to 5 seconds steady circular yellow illumination phase prior to transitioning to the steadily illuminated circular red condition. The gate arm shall begin its descent 3 seconds to 5 seconds after the circular red lens is illuminated. To permit road users to proceed. The AFAD shall display a flashing circular yellow lens and the gate arm shall be in the upright position. To transition to circular yellow condition, the gate arm shall begin its ascent to an upright position simultaneously with the start of the illumination of the flashing circular yellow lens.
104.22.03 03 Flaggers. Provide certified flaggers on-site and use one of the following methods
to operate the AFAD(s):
a.Method 1 – Place an AFAD at each end of the work area.
b.Method 2 – Place an AFAD at one end and place a flagger at the opposite end. The flagger operating the AFAD shall be able to view the device and the approaching traffic during the operation.
104.22.03 04 Cones. Install cones according to the MdMUTCD, the Book of Standards, the
Contract Documents, and the following:
a.Install a minimum of 11 cones spaced at 20 ft maximum along the center line on the approach to the AFAD.
b.Use a minimum of 7 cones to form the shoulder taper to delineate the AFAD.
104.22.04 Measurement and Payment
104.22.04 01 Automated Flagger Assistance Device will be measured and paid for at the Contract
price per unit day per each Automated Flagger Assistance Device. 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 Automated Flagger Assistance Device will be paid for only once per unit day, regardless of how many times it may be relocated. When an Automated Flagger Assistance Device is used for part of a day, it will be measured and paid for as a unit day. The payment will be full compensation for the Automated Flagger Assistance Device, and for all material, labor, equipment, tools, and incidentals necessary to setup and operate the Automated Flagger Assistance Device at the site as required and at any relocated site as specified or as directed. When operations require 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS continuous 24 hour use of an automated flagger assistance device, the unit day will be measured as 24 hour periods from start to finish.
104.22.04 02 Certified flaggers to operate the Automated Flagger Assistance Device will be
measured and paid for at the Contract unit price per hour as specified in 104.15.04.
104.22.04 03 Cones to delineate the center line in the approach to the Automated Flagger
Assistance Device and form the taper in front of the Automated Flagger Assistance Device will not be measured but the cost will be incidental to the Contract unit price for Automated Flagger Assistance Device.
104.22.04 04 Automated Flagger Assistance Device related signs (R1-7, R1-8, R10-6, R10-6a)
will not be measured but the cost will be incidental to the Contract unit price for Automated Flagger Assistance Device.
104.23 Protection Vehicle (Pv)
2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS CATEGORY 100 PRELIMINARY SECTION 104.23 — PROTECTION VEHICLE (PV)
104.23.01 Description
Furnish a PV as required. The PV shall consist of a work vehicle with approved flashing lights as required by the standard TCP’s and either:
a.A truck-mounted attenuator (TMA) with support structure designed for mounting the system to the work vehicle, or
b.A trailer truck-mounted attenuator (TTMA) designed for attaching the system to the work vehicle by a pintle hook. Provide an arrow panel (arrow mode for multilane roadways and caution mode on two-lane, two-way roadways) in accordance with 104.07.03. The arrow panel shall be integral to either the work vehicle or the TMA/TTMA. No part of the TMA/TTMA shall be designed to intrude under the support vehicle during impact or require a safety clearance under the support vehicle that extends forward of the rear axle. General. The ballast of the work vehicle shall meet the manufacturer’s specification for the TMA/TTMA and be firmly secured to prevent movement during an impact. All exposed steel on the attenuator shall be primed and painted yellow. The undercarriage and support frame may be primed and painted black. All welding shall be performed by or under the direct supervision of a certified welder. The rear facing surface of the TMA/TTMA shall have an inverted "V" chevron pattern formed by alternating 4 in. wide black and yellow stripes as shown in Standard No. MD 104.01-19C. The sides of the TMA/TTMA shall have a border of 4 in. red and white reflective tape as shown on Standard No. MD 104.01-18A. The TMA/TTMA shall have a standard lighting system including brake lights, tail lights, turn signals, and ICC bar lights. All wiring shall be protected and adequately supported. The TTMA trailer shall conform to Maryland Motor Vehicle Law governing trailers.
Source: Maryland Standard Specifications for Construction and Materials, 2025 Edition. Pages 199–203 of 1,113.