Traffic volumes on local roadways continue to grow with the increase in valley population. Traffic control is necessary for the safety of the traveling public, including motorists, pedestrians, or bicyclists. The Nevada Revised Statutes section 484.781 provides that all traffic control devices used by local authorities must conform to the manual and specifications adopted by the Nevada Department of Transportation. Therefore, Clark County Public Works relies on the Manual on Uniform Traffic Control Devices, as adopted by NDOT, to determine when and where a traffic control device is required or warranted.  

Traffic Studies, Design and Review
The Traffic Management Division provides in-house review of designs for traffic control-related devices (traffic signs, pavement markings, traffic signal systems, intelligent transportation systems and streetlight systems) for County-funded projects designed by either the Public Works Design Division or County-hired private consultant engineering firms. Traffic Management also provides the design work for traffic signals and Traffic Improvement Projects (TIP) funded by the Regional Transportation Commission for the County.

Traffic Operations and Maintenance

Traffic Signals

Warranted traffic signals installed in accordance with Nevada Revised Statute 484.781 can provide the following benefits:

• Promote the orderly flow of travel along major routes.
• Allow cross traffic to move with minimum delay and maximum safety.
• Reduce the frequency of certain types of accidents and vehicle emissions.

Traffic signals can also have negative effects and legally cannot be installed unless one or more of the eight signal warrants are met. An investigation of the need for traffic signal control must include, where applicable, an analysis of the factors contained in the eight warrants. However, the satisfaction of a warrant or warrants is not in itself justification for a signal. Intersection layout, turning movements, peak hour delays, vehicle types and volumes, pedestrian flow, vehicular speeds and accident history are all factors to be considered. When traffic signals are installed without sufficient justification, the results may include: increased traffic accidents, such as rear-end collisions; excessive delay and congestion; diversion of traffic to less appropriate routes such as cut-through traffic on residential streets; the intentional disregard of signals and traffic signage; and an increase in vehicular emissions.

Signals may be installed as part of an intersection improvement effort, as a component of a larger road project, or by a private developer whose project is expected to generate traffic impacts in the immediate area. The participation level required of each developer is proportional to the incremental traffic impacts created by the new development. The average cost per signal is approximately $350,000.

Streetlighting

The Streetlighting Unit is responsible for the maintenance, upgrade and repair of streetlights and electrical service points throughout Clark County. Streetlight poles are replaced when severely damaged from accidents or when potential safety and liability problems exist due to deterioration. The Traffic Management Division initiated a streetlight modernization program using the Regional Transportation Commission of Southern Nevada (RTC) for replacement of older incandescent and mercury vapor systems with high-pressure sodium luminaires and multiple circuits, as part of RTC roadway projects. This has allowed the upgrade of a substantial number of streetlight systems on major County streets. Another streetlight modernization program is in place that involves improvements constructed by public sector, County forces (retrofits and small projects) and the private sector (contractors). Clark County Public Works Traffic Management also provides streetlight maintenance services on state highways within Clark County through an intergovernmental agreement with Nevada Department of Transportation.

Traffic Signs and Pavement Markings

These units perform maintenance services on County road traffic control signs and pavement markings. These activities include the installation, repair, maintenance, and removal of traffic signs, street name signs and pavement markings; and the testing and evaluation of new traffic control materials and devices. The most common requests received is for the installation or removal of stop signs. A stop sign assists drivers and pedestrians to determine who has the right-of-way at an intersection. Stop signs are intended to stop traffic, not control speeds. In fact, traffic studies have indicated that accidents actually increase when stop signs are used improperly. A variety of other measures can be used to address local traffic issues such as limited parking near intersections to improve driver visibility and reduce accidents.