Our Real Time Information (RTI) system, provided by Star Trak, is in place along certain routes in Derby. This system is managed by Leicester City Council in partnership with Derby City Council.
The system provides up to date bus arrival information for passengers waiting at bus stops. They display the number of minutes that passengers can expect to wait before the arrival of the bus. Onboard the bus, the RTI unit displays and announces the next stop. This page has information on:
RTI bus stops and locations
Real Time Information (RTI) units work by sending a signal from a bus to an RTI sign using satellite and radio communications. The signal from the bus is used to locate it along its route. A computer system uses this information to predict how long it will take the bus to reach the stop.
The data is relayed every 30 seconds and the location of the vehicle and its estimated time of arrival is updated accordingly. There are RTI signs currently located in Allestree (Allestree Red and Allestree Blue service), Chaddesden (22,24 and 26 services), Chellaston (60, 61, 68 and 68a services), Spondon (Spondon Flyer Red and Spondon Flyer Blue services) and along London road (Airline Shuttle service) and Nottingham Road (Rainbow 4 and Rainbow 5 services). To find out where your nearest RTI bus stop is please visit the star trak website 
.
How does RTI work?
We have provided both a graphical animation and a text description to show how the RTI system works.
Text Transcription
Slide 1
The bus is travelling along the road towards the next bus stop; there is a satellite orbiting the earth which sends data to a computer system. Other vehicles are travelling along the road as well.
Slide 2
As the bus travels, the satellite locates the position of the bus using a Global Positioning System (GPS). This information is sent to the computer system, which then calculates the time it will take the bus to get from its current location to the bus stop – in this example, seven minutes. This value of seven minutes is then sent to the RTI sign over a radio link and is displayed. Other vehicles are still travelling along the road.
Slide 3
As the bus travels down the road the satellite relocates it every thirty seconds and, using the same method as slide 2, the RTI sign is updated with the new estimated arrival time. The bus has now moved further on down the road and the sign now displays four minutes. Other vehicles are still travelling along the road.
Slide 4
As the bus travels down the road the satellite is still locating it every thirty seconds. The RTI sign is updated with the new time. The bus has now moved further on down the road and the sign now displays two minutes. Other vehicles are still travelling along the road.
Slide 5
Once again, the satellite tracking has updated the position of the bus and the computer system has calculated a new arrival time. The bus has now moved onto the stop and the sign now displays zero minutes. Other vehicles are still travelling along the road.
Is my RTI working properly?
Our Real Time Information (RTI) system is up and running. There are, however, some situations when a fault may occur. These faults are displayed on the RTI units. The following images show the various faults that may occur.
Here, the RTI is showing a dot. This means that the unit is not getting a signal from a bus on that route. This may mean that the onboard bus unit is not working or a bus without an onboard unit is being used.
This RTI unit is blank. This is an RTI unit fault - please use the contact form below to report this fault.
This RTI unit is showing double dashes. This is an RTI unit fault - please use the contact form below to report this fault.
This RTI unit is showing two single dashes. This is a signal fault at the RTI unit - please use the contact form below to report this fault.
This RTI unit is showing a single dash. The RTI unit is receiving a signal, but not for the usual bus service - please use the contact form below to report this fault.
This RTI unit was displaying a time but then went down to zero. It then displayed another time value without any bus arriving. This is an RTI unit fault - please use the contact form below to report this fault.
Another common action, which could be seen as a fault, is the RTI unit showing a continuous time that doesn’t change, for example, displaying 8 minutes for a duration of 2 minutes. The RTI units show the actual time it will take the bus to get to that RTI unit. However, if a bus is at a standstill, for example in a queue of traffic, then the RTI unit will not alter the estimated arrival time in order to compensate for the delay.
We have provided both a graphical animation and a text description to show the effect that queuing has on the estimated arrival time.
Text Transcription
Slide 1
The bus is travelling along the road towards the next bus stop; there is a satellite orbiting the earth, which sends data to a computer system. Other vehicles are travelling along the road as well. As the bus travels, the satellite locates the position of the bus using a Global Positioning System (GPS). This information is sent to our computer system which then calculates the time it will take the bus to get from its current location to the bus stop – in this example, six minutes. This value of six minutes is then sent to the RTI sign over a radio link and is displayed.
Slide 2
As the bus travels down the road the satellite relocates it every thirty seconds and, using the same method as slide 1, the RTI sign is updated with the new estimated arrival time. The bus has now moved further on down the road and the sign now displays four minutes. However a set of traffic lights has turned red and the bus is now in a queue. Other vehicles are still travelling along the road.
Slide 3
The bus is still queuing at the traffic lights. The satellite still relocates it every thirty seconds and, using the same method as slide 1, the RTI sign is updated with the new estimated arrival time. As the bus hasn’t moved, the sign still displays four minutes. Other vehicles are still travelling along the road.
Slide 4
The bus is still queuing at the traffic lights. The satellite still relocates it every thirty seconds and, using the same method as slide 1, the RTI sign is updated with the new estimated arrival time. As bus still hasn’t moved the sign still displays four minutes no matter how long it remains in the queue. Other vehicles are still travelling along the road.
Slide 5
The lights have now turned green. The satellite is still locating it every thirty seconds. The RTI sign is now updated with the new estimated arrival time. The bus has now moved further on down the road so the sign now displays three minutes. Other vehicles are still travelling along the road.
Slide 6
Once again, the satellite tracking has updated the position of the bus and the computer system has calculated a new arrival time. The bus has now moved further down the road and the sign now displays two minutes. Other vehicles are still travelling along the road.
RTI units on board the bus 
The units send a signal to the RTI bus stop. They also display and announce the next stop to the passengers onboard the bus.
Bus Services that are due to have RTI soon
We are pleased to announce that The Mickleover service is due to have RTI up and running in 2008.