Item 401XXX - Construction Vehicle Detection, CCTV,
and Signal Communications
1.0 Description
For all construction projects in the City of Scottsdale with duration of 15 days or
more, temporary vehicle detection will be required for all approaches at signalized
intersections that currently have loop detection which will be disturbed by the
construction. In addition, traffic signal communications (telephone or other) to the
central signal computer and CCTV (if present) shall be maintained continuously during the
course of the project. Work under this item shall consist of furnishing all labor,
equipment and materials necessary to install temporary traffic signal detection, and
maintain signal communications. The contractor or sub- contractor through the life of the
project shall maintain the detection zones and communications by ensuring full
functionality 24 hours a day, 7 days a week.
The contractor shall be responsible for the ongoing operation of the detection
equipment, which may require redeployment of detection zones as traffic barricading and
lane use changes require.
This work shall be performed as specified herein and as directed by the City's
Construction Manager, Traffic Engineering and Signal Maintenance Departments.
2.0 Materials
The contractor shall be responsible to purchase, or lease video detection, microwave
detection or temporary loop detection equipment that will fit the lane use requirement of
the project and will be compatible with existing control equipment. Equipment can be
installed in a temporary fashion and must be well protected from vandals and doesn't
create tripping hazards for pedestrians.
If Video Detection is selected for the project, wireless communications from the camera
to the control cabinet shall not be used. All detection devices shall be hardwired from
the detector to the cabinet using either new conductors or available spares in the
existing signal cables.
The traffic signal control cabinet cannot be modified or reconstructed in any way. No
additional cabinets shall be affixed to the signal control cabinet. However, temporary
NEMA style cabinets may be installed on the traffic signal poles, and must be at least 12'
from ground level on the curb side of the pole only. No additional equipment shall block
the site distance of a traffic signal or pedestrian indication.
3.0 Construction Requirements
Contractors may run temporary overhead wiring for detection or communications if not in
conflict with overhead power lines or construction equipment working in or through the
intersections.
All detection shall be operated in the presence mode. Locked detection will not be
allowed.
All equipment used shall be submitted for approval through the Construction Manager in
accordance with all equipment submittal requirements.
Mounting of detection equipment shall not damage existing poles, or new poles to be
installed at the intersections. Metal banding shall be allowed for installation of
cameras, microwave, or other detection devices. No new holes shall be drilled in the
traffic signal poles, which are to remain.
The Contractor shall be required to keep the detection equipment, communication, and
CCTV links in complete operational order through the life of the project. Should a
detector fail, a City of Scottsdale Traffic Signal Technician will respond to the
intersection and place the signal controller in a "recall" mode of operation.
The contractor, or factory representative will be notified to repair the defective part
within four hours after being notified of the problem. Once repaired, the contractor shall
notify Scottsdale Traffic Signals Department to remove the intersection recall for that
movement.
The communication link to the traffic signal controller shall be repaired within four
hours after the Qwest phone drop location is relocated. The contractor is responsible to
coordinate with Qwest to ensure a timely relocation of any traffic signal communication
link. CCTV links shall be repaired within 24 hours.
4.0 Method of Measurement
The detection equipment shall be measured as a complete unit per approach being
detected, installed, operational and maintained during the life of the project.
There is no pay item for the maintenance of the traffic signal communication link. The
cost of maintenance and repair of the phone link shall be incidental to the traffic signal
reconstruction project.
5.0 Basis of Payment
The placement, maintenance and repair of the temporary vehicle detection system shall
be paid as measured. Contract unit prices shall be full compensation for work described in
the special provisions and as shown on plans, complete and in place.
There will be no additional payment for the maintenance and repair of the communication
links to the traffic signal controllers. |
