3. Current UTC Systems in South Africa
3.1 Remote Monitoring Systems
Remote Monitoring Systems (RMS) are traffic control systems that connect a roadside controller to a central computer to provide a remote monitoring facility at the traffic signal equipment. RMS offers functionality that allows it to monitor digital inputs and outputs, phase outputs and phase lamp monitoring. In the occurrence of any faults, the system connects to the in-station, alerts the operator and lodges the fault simultaneously (Imtech Traffic and Infrastructure UIC Ltd).
In addition, these systems offer a range of other features such as traffic data collection, remote clock setting and loading of signal plan configurations. Communication between the roadside controller …show more content…
This offers significant speed advantage in any unplanned event. UTC systems also offer full monitoring facilities along with traffic flow enhancing facilities such as Traffic Responsive Plan Selection (TRPS), where the system generates signal timing plans on the basis of traffic demand.
Wire based communications are used for reliability and quick message turn around. In the event of a communication fault, UTC systems have robust backup plans driven by the roadside controller.
3.3 SCOOT Control
SCOOT (Split, Cycle and Offset Optimisation Technique) was introduced to different parts of South Africa in the late 1980’s and early 1990’s. SCOOT based systems offer microscopic real time adjustments to signal timing parameters according to real traffic demands in comparison to the macroscopic adjustments produced by TRPS. This means that signal timings are adjusted to suit any arriving traffic patterns.
The SCOOT central computers are linked to a UTC system which produces traffic patterns, determines optimal traffic signal timings and thereafter instructs the UTC system to display the settings on a …show more content…
Types of slip lanes
There are two types of slip lanes that are considered, namely:
• Free Flowing Slip Lanes, and
• High Entry Angle Slip Lanes
7.1 Free flowing slip lanes
These lanes can be recognised by an exclusive lane that merges with the desired roadway.
Free flowing slip lanes are lanes that provide a continuous, diverted left-turn lane from the intersection and allows turning vehicles to join the desired roadway with ease and with no required yielding.
These lanes are generally separated by raised islands and caters for safe pedestrian crossing.

7.2 High Entry Angle Slip Lane
These slip lanes can be identified by the lack of an exclusive merge lane with the desired roadway.
High entry angle slip lanes are left-turning lanes that are diverted from the through traffic of an intersection and has the same functionality as that of the free flowing slip lane, however, requires a yielding motion at the approach to the desired roadway.
There are two recommended options of high entry angle slip lanes that can be considered:
• ‘Give-Way’ controlled slip lanes,