Traffic Signal Arm

Keywords
About: transportation, traffic control, pavement marking, traffic cabinet, camera, traffic detector, traffic pole, push button, signal, signal arm, Manual of Uniform Traffic Controls, MUTCD, Transportation Operation Agency, TOA
Taking place at: Washington, D.C., DCGIS, DC GIS, District of Columbia, DC

Abstract

The dataset contains location and attributes of traffic controls located at each intersection in the District of Columbia. All traffic poles, pavement markings, traffic cabinets and cameras located within 10 meters of curb face intersections are collected. Poles must support traffic control devices in order to be collected. This includes traffic control signs, traffic signals, traffic arms and cameras. The data set does not include poles supporting only name plate signs and parking enforcement signs.

Purpose

This data is used for the planning and management of traffic controls - Assets, Activities, Incidents, as well as the maintenance of Traffic Pole Features of the District of Columbia, Department of Transportation (DDOT).

Access constraints

Contact DDOT / OCTO GIS. Any data obtained outside of DDOT / OCTO GIS are unauthorized copies.

Use constraints

Data cannot be redistributed in any manner without written authorization. DDOT-OSAT / OCTO makes no claims as to the completeness, accuracy or content of any data contained hereon, and makes no representation of any kind, including, but not limited to, the warranty of the accuracy or fitness for a particular use, nor are any such warranties to be implied or inferred with respect to the information or data furnished herein.

Point of contact

Markos K. Yeterawork
in DC Department of Transportation, Operational Support and Applied Technology (OSAT) - Spatial Data Systems Division



phone: (202) 741-5391
fax: (202) 727-5660
hours: 8:30 am - 5 pm

Credits

District of Columbia, Department of Transportation.
Operational Support and Applied Technology (OSAT) - Spatial Data Systems.

Data accuracy

Accuracy

Mercado will achieve 95% attribute accuracy on a maximum 10% random sample in order for data to be deemed acceptable. Collected attributes will be evaluated against field conditions and the calculation of accuracy will be based on total countable collected attributes. TrafficPole attributes will be quality controlled to an accuracy of 95% based on each counted attribute receiving equal weight. Attributes collected are as follows:

PoleID
SteetJunctionID
StreetJunctionID
StreetSegID
PoleType
PoleMaterial
PoleHeight
PoleCondition
BaseType
IsPower
IsAPS
NoOfHeads
Picture

Logical consistency

Consistency of the data is manually checked by a GIS technician to test the accuracy of the data at the completion of each ward. For each PoleType there are typical attribute vallues. Mercado Consultants has developed a proccess for checking the logical consistency of the data. The select by attributes tool is used to select features whose attributes do not fall into typical values expected for a particular feature class. For example, PoleTypes labeled Streetlights typically have PoleHeights valued between 25' and 30'. Streetlights with PoleHeights with value greater the 30' or lesser then 25' are selected and checked against the pole's picture and adjecent poles.

See Process Description under the Process Step to understand how logical consistency is achieved for each Traffic Pole at each street intersection.

Completeness

Mercado Consultants, Inc. performed an inventory of traffic poles at each intersection within the District of Columbia. The inventory was conducted in all of the Washington DC. The TrafficPole inventory includes the following items:

The collection of assets' attribute information as described in the Attribute Accuracy section of the Data Quality tab.

The collection of sub-meter GPS on traffic controll assets as described in the Positional Accuracy section of the Data Quality tab.

A supplemental datat set indicates all StreetIntersectionIDs without assets and an explanation. This data set will provide a completeness report.

Horizontal positional accuracy

All traffic control assets are inventoried and placed relative to DDOT's source road network. The location of assets are established by using three different methods:

1. First, a sub-meter gps point is taken for each traffic pole with the exclusion of underpasses and tunnels. Each sub-meter gps point is stored in Trimble formatted .SSF files. The .SSF files are differentially corrected and exported to the NAD83 Maryland State Planes Meter coordinate system using Trimble's GPS Pathfinder Office software program.

2. In areas where a good satelite signal could not be established, locations are established from the intersection of two radial measurements from known locations on the existing DC planametrics.

3. GPS position are also established by digitizing the locations using 2008 Orthophotos.

Vertical positional accuracy
No elevation value was collected

Lineage / Sources

Lineage / Processes

Ryan Spielman in Mercado Consultants phone: 301 260 0090 fax: 301 260 0018 hours: 8:00am to 5:00pm

Mercado developed a controlled QA/QC process that requires a GIS technician to manually check the accuracy of the data using Arc GIS software. The QA/QC process includes the following checklist: Location of poles are accurate based on orthophotos and existing planametrics. Each required attribute is correctly filled. Each TrafficPole and TrafficSign feature is hyperlinked to a photo. Each asset on the pole are correctly related to the pole based on the picture taken of the pole.

Distribution

Contact DDOT/TSA

Distribution liability
DDOT (OSAT) / OCTO makes no claims as to the completeness, accuracy or content of any data contained hereon, and makes no representation of any kind, including, but not limited to, the warranty of the accuracy or fitness for a particular use, nor are any such warranties to be implied or inferred, with respect to the information or data furnished herein. Subject to terms and conditions of the Memorandum of Agreement. Memorandum of Agreement must have authorized signature.

Distributed by
Markos K. Yeterawork
in D.C. Department of Transportation. Operation Support and Applied Technology (OSAT) - Spatial Systems Division



phone: (202) 671 2123
fax: (202) 727-5660
hours: 8:30 am - 5 pm

Entity

Traffic Signal Arm / DDOTGIS
Traffic signal arm is mounted on a traffic pole

Attributes

• OBJECTID / ESRI
  Internal feature number.
• SIGNALARMID
  
• POLEID
  
• EQUIPMENTID
  
• MASTARM
  
• LENGTH
  
• HEIGHT
  
• NOOFHEADS
  
• SignalArmID
  
• PoleID / Mercado Consultants
  Unique traffic pole id
  • Whole number / Unique sequential number generated by Terrasync software on Trimble XT
   
• EquipmentID
  
• MastArm
  
• Length
  
• Height
  
• NoOfHeads / DC Department of Transportation, Operational Support and Applied Technology (OSAT) - Spatial Data Systems Division
  Number of Signal on Pole

Entity

TrafficPoleHasSignalArms / DDOTGIS
TrafficPole supports a signal arm

Attributes

Entity

TrafficPoleHasPushButtons / Mercado Consultants
TrafficPole supports a push button signal

Attributes

Metadata

FGDC Content Standards for Digital Geospatial Metadata / FGDC-STD-001-1998 as of 20110107


Provided by
Markos K. Yeterawork
in DC Department of Transportation, Operational Support and Applied Technology (OSAT) - Spatial Data Systems Division


REQUIRED: The city of the address. REQUIRED: The state or province of the address., REQUIRED: The ZIP or other postal code of the address.,

phone: (202) 741-5391
fax: (202) 727-5660
hours: 8:30 am - 5 pm