Glossary of Terms for Transportation, Traffic and Signalization- Chapter 4

Travel Speed: The ratio of the distance a vehicle takes to the time it travels in a road including stopping durations.

Travel Duration: The average time spent by vehicles passing a road section, including the control delay.

Signalization Status: Phase diagram which shows phase plan, loop duration, green duration, yellow duration and protection duration in a signalized intersection.

Lane Distribution: The parameter which volume distribution differs greatly according to the traffic distribution, traffic compound, speed and volume, the number of access points and location, beginning and finishing models of drivers, driver habits and environment development when two or more lanes usable for one-way traffic.

Lane Group: A series of lanes that established at intersection approach for separate capacity and service level.

Demand: Number of vehicle/pedestrians requesting service in the highway system.

Full Traffic-Actuated Control: A signal communication mode controls vehicle or pedestrian sensors that each direction of intersection approach, creation of each phase and current duration.

Design Speed: It is the speed used to determine the design characteristics of different geometric elements of the road platform.

Design Hour: The number of vehicles per hour that best represents the volume of traffic for the design of a highway facility.

Total Delay: The total of all delay times for any lane group.

Total Loss Time: The total of time which not used effectively in a signal loop in any turns at intersection.

Approach: Lane group that combining all left turns, right turns and move straight currents coming to the intersection.

Side Road: The second priority road which controlled by stop signs in a two direction stop controlled intersection.

Semi-Traffic Actuated Control: It is a signal communication mode that determine the signal durations by the data from the sensors.

Pedestrian: Person who travels on foot.

Pedestrian Current Ratio: Number of pedestrian pass from one point to another in 15 minutes.

Pedestrian Crossing: The area separated and marked on the road to allow pedestrians to cross over the intersection.

Green Time: Amount of green duration in seconds in a signalized intersection.

Duration Between Green to Green: The time between the end of the green signal given to one of the currents at intersection, that is, from the phase change point to the start of the green signal for the other phase, is called the inter-green period. the sum of all red and yellow periods between the two phases.

Annual Average of Daily Traffic: It is the ratio of the total volume of traffic passing in both directions during a year to the number of days in the year.

Density: The average number of vehicles located within the defined area in a part of roadway.

Peak Hour Factor: It is defined as the ratio of peak hour traffic on a road to the maximum current rate at that peak hour.