CIV E 482 Research Paper
Traffic Operations

Alishia Ballard
Fall 2014

Index 1. Example of Traffic Operations District 4 Caltrans………………………Page 3 2. Traffic Signals…………………………………………………………….Page 7 3. Elements of Design……………………………………………………….Page 9

CIV E 482 Research Paper
Traffic Operations
Example of Traffic Operations District 4 Caltrans

To get a better understanding of traffic operations it is key to understand a specific office within the traffic operations field here in the state of California. According to the California Department of Transportation in District 4’s online informational, which is responsible for the Bay Area, their division of traffic operations consists of 320 technical and administrative staff within nine offices. These offices are responsible for planning, design, and analysis of highway safety and traffic operational improvements. This specific office does what most office in California offices of traffic operations do; they manage traffic activities and operations. We can take a brief look into what all nine of the offices do, and what it is they are responsible for. The office of traffic operations strategies (TOPS) addresses congestions trip reliability and safer with the use of better system management and new technologies according to the Caltrans website. The TOPS management provides guidance and establishes priorities for traffic operation strategies, which support corridor and system-wide transportation improvements for Corridor System Management Plans (CSMP) and Corridor Plans (CP) (Caltrans “District 4”). The TOPS Management also focuses on the implementation of the identified projects, working with the district functional units to ensure the projects are scheduled, designed and constructed (Caltrans “District 4”). They also promote connecting Caltrans districts and encourage local and regional partnerships. Another office within District 4 is the Office of electrical design and operations. They design and review all electrical system projects in the district for traffic signaling, highway lighting, ramp meters, changeable message signs (CMSs), closed circuit television cameras (CCTVs), highway advisory radios (HARs), fog horns, navigational and warning lights on bridge structures, planned improvements in toll-bridges and tunnels, power distribution and toll collection supervisory system control systems (Caltrans “District 4”). This office also develops software for the signals and signal system operations (Caltrans “District 4”). The office of electrical systems does the traffic operations systems (TOS) equipment. Some TOS equipment, is traffic monitoring stations, ramp meter system, CCTVs, changeable message signs (CMSs), HARs, and extinguishable message signs (EMSs) (Caltrans “District 4”). This office also provides support for the traffic management center (TMC), which compiles, mojitos, and disseminates traffic information to minimize the impact of traffic. Additionally this office reviews the design of the systems developed by outside consultants to cooperate with the Metropolitan Transportations Commission by integrating TOS components into a compatible system for the integration with the TMC (Caltrans “District 4”. The office of highway operations performs all the traffic operational analyses for the freeway, interchange and intersection in support of the project scope documents, environmental clearance, project alternative analysis, project design, and corridor studies for projects that Caltrans leads (Caltrans “District 4”). They also take care of the transportation management plans by providing lane closure hours, detour routes, assessment of traffic delays, and contraction support (Caltrans “District 4”). With the use of Performance Measurement systems (PeMs), the office is able to manage freeway congestion. This office also works with the MTC and CHP to manage the high occupant vehicle (HOV) lanes and the express lanes on freeway facilities (Caltrans “District 4”). This office is responsible for updating the traffic census and inventory data. They investigate and respond to complaints regarding traffic operations from motorists and local and state officials, identify operational improvement projects, review IGR/CEQA documents and encroachment permits, and coordinate with the tolling authority on the operation and proposed improvements for all state operated toll bridges, which includes FasTrak lanes. This office contributes to research of any related traffic flow, HOV lanes, and high occupancy/tool lanes. The office of encroachment permits processes permit application and issues permits for highway improvements to construct approved facilities or to conduct specific activities. This office has a main focus of protecting, maintaining and enhancing the quality of the state highway system during and after permitted work to ensure the safety of both the highway users and the permit applicant. These specific duties protect the State;s investment in the highway facility and documents temporary uses of highway right of way special events, filming, etc (Caltrans “District 4”). The office of traffic safety has a primary concern for the assessment and analysis if traffic safety on state highways. The office is responsible for the design of signing and striping for the highways and freeways in the district, maintaining of sign logs and accident records, provides service to the district claims and legal support offices, conducts speed zone studies and administers the district traffic safety program (Caltrans “District 4”). This office investigates traffic safety complaints and operational problems. The odd ice, additionally, administers and develops project study reports (PSRs) and Project Reports (PRs) for the purpose of programming projects to the state highway operation and protection program (SHOPP) for safety or operational improvements (Caltrans “District 4”). The office of traffic management emphasizes the importance of traffic management and inclusion of related components in all construction, maintenance and permit activities on the state highway system (Caltrans “District 4”). This office provides services in the lane closure system unit, which reviews, approves and coordinates lane closures from construction and so forth on freeways and highways to help minimize traffic impacts to the public (Caltrans “District 4”). Also the traffic management team unit provides field traffic management to help with changeable message sign that provides motorists with information of any incidents, non permitted special events, any high profile or sensitive closures. Lastly they work with the transportation management center to provide real-time system wide management services to monitor and manage traffic flow and provide information to motorists. This office operates on a 24 hours a day schedule and partners with Caltrans, CHP, and MTC (Caltrans “District 4”). The traffic systems office is responsible for reviewing, planning, and developing TOS for the district. They do much of the same activities as the office of traffic operations. Additionally, they are responsible for the district’s park and ride lot system. They are involved with disaster planning and incident management due to any natural or manmade cause (Caltrans “District 4”).

Traffic Devices Many aspects go into traffic operations. One of those aspects are traffics devices. The use of traffic devices includes the fundamentals of traffic control devices, traffic signs, pavement markings and delineation, traffic signals, temporary traffic control devices, intelligent transportation systems (ITS), and operation and maintenance of devices. According to the California Department of Transportations website, Cal Trans’ Traffic control devices branch is in charge of the rules and regulations contained in the California Manual on Uniform Traffic Control Devices (CA MUTCD) regarding signs and temporary traffic control. They provide the standards and specifications for official traffic signs to be used on the streets and highways of California. Among that responsibility, the traffic control device branch is responsible for the standard specifications, plans and special provisions pertaining to signs and traffic control on State highway construction projects. The Highway Design Manual has some traffic considerations such as pedestrians, bicyclist, and drivers. All forms of travel are highly considered in the uses of traffic operations. Although you may not believe the height of your vehicle is important, it is. Clearance for overhead signs and signals is a traffic consideration based on the vehicle characteristic, height (HDM 400-2). Intersections are an aspect traffic control. Some intersection control options to consider are two-way stop for minor road traffic, all-way stop control, signal control, and yield control (roundabout) (HDM 400-3). Unsignalized intersections for minor street movement can lead to signalization once traffic becomes backed up and the level of service is horrible enough that the traffic caps are not sufficient to allow drivers to be aware of the pedestrian crossing (HDM 400-3). Pedestrians should not be prohibited from crossing any direction of an intersection unless there is no safe route. They may be prohibited if there is a reasonable route and the need is there (HDM 400-4). Transit is a very important in the design phase because their needs must be met. The needs of transit can have a large impact on the performance of an intersection (HDM 400-4). The stops must be planned around the vicinity of intersections and they must evaluated to permit the safest way of operating the intersection (HDM 400-4).

Elements of Design Another aspect of traffic operations are the elements of design. Within elements of design there are many characteristics. The functional classification of roads, the vehicle operating characteristics, horizontal and vertical alignments, sight distance, cross sections elements, intersection design, and freeway and grade separated intersections all are elements of design. Sight distance is covered extensively in the Highway Design Manual. The four types of sight distance include passing, stopping, decision and corner (HDM 200-1). Passing sight distance is used when another lane allows for a passing opportunity (HDM 200-1). Stopping sight distance is the minimum distance for a design speed to be provided on multilane highways and on double lane roads when the passing sight distance is not economical (HDM 200-1). Stopping sight distance is provided for all modes of transportation, including motorists and bicyclists, on all types of interchanges and intersections (HDM 200-1). Decision sight distance is used for major points of decision making while driving (HDM 200-1). Corner sight distance is used at intersections (HDM 200-1). Horizontal alignments are for safe and continuous operation at a design speed for long lengths of the highway (HDM 200-12). Major considerations involving horizontal alignment include the design for safety, profile, type of facility, design speed, geotechnical features, topography, right of way cost and construction cost (HDM 200-12). Safety can be directly or indirectly considered in the design element of traffic controls (HDM 200-12). Right of way is a consideration for alignment most likely on freeways in metropolitan areas (HDM 200-12). The topography of an area is a controlling factor for curve radius and design speed (HDM 200-12). Moreover, design speed controls sight distance, but the sight distance must be considered with the topography due to the demand of a larger radius than the design speed (HDM 200-12). All those factors must be considered to produce an alignment which uses the various elements of design to be a safe yet cost effective highway (HDM 200-12). Horizontal alignment provides the minimum stopping sight distance is chosen based on the design speed at all points on a highway (HDM 200-12). Standards for the minimum radius of curve are determined by specific design speeds (HDM 200-16). The pass sign sight distance information in the California Manual on Uniform Traffic Control Devices (California MUTCD) is based traffic operational criteria (HDM 200-2). There has to be coordination of horizontal and vertical alignment. The proper balance between curvature and grades should be executed (HDM 200-22).

Works Cited Page
Highway Design Manual. Chapter 200 Geometric Design and Structure Standards, 7 Mar. 2014. Web 4 Nov. 2014. <blackboard.sdsu.edu>

Highway Design Manual. Chapter 400 Intersections at Grade, 7 Mar. 2014. Web 2 Nov. 2014. <blackboard.sdsu.edu>

The California Department of Transportation. California Manual of Uniform Traffic Control Devices, 2014. Web 6 Nov. 2014. <dot.ca.gov>

The California Department of Transportation. District 4 Division of Traffic Operations, 2014. Web 6 Nov. 2014. <dot.ca.gov>