When you open the Telraam website, the main map shows traffic data collected from Telraam sensors. In the bottom right corner you can change what data is displayed on the map. You can chose between:
Three different layers (from left to right):
Live traffic (default)
Historic traffic
Relative traffic [Beta]
The visualised mode of transport (by default it is the total traffic including all road users) and the V85 speed.
LIVE TRAFFIC
The Live traffic layer shows the most recent full hour's total traffic volumes for segments with operational Telraam sensors at the moment.
For simplicity, we also show:
Segments with recently registered devices which have not produced data yet
Segments where a Telraam device was active very recently, even if it is not now (until up to one week after the last measurement)
Colours on the map:
The darker the colour, the higher the traffic volume
Grey is used (across all modes and layers) to represent segments where data is not available - for a variety of possible reasons
The colour scale is explained in the bottom right corner of the page
Delay in the live data:
Because of data processing, there is always a short delay between actual live traffic and what appears on this page.
For example:
Traffic for 12:00–13:00 will only become available around 13:15–13:20
Subscribers have access to (device-level) data with practically no delay
HISTORIC TRAFFIC
The Historic traffic layer shows all segments where (public) Telraam measurements have taken place at any point in the past.
This means:
You can access data from previously active or currently inactive Telraam segments
Each segment visualises the average observed traffic parameters for:
The current day of the week, and
The current hour of the day
These averages are based on the last year of measurements for each given segment.
Example:
If you look at this map on a Thursday at 15:25, it will display the average observed traffic for Thursdays between 15:00 and 16:00.
RELATIVE TRAFFIC [Beta]
The Relative traffic layer is our newest (experimental) addition.
It combines information from the previous two layers and takes things one step further.
It shows how busy (or fast, when V85 is selected) the streets with live data are relative to what we expect from the last 3 months of observations.
How it works:
If the currently observed traffic is about the same as what the average traffic was for this day of the week and time of day over the past 3 months, then the traffic is marked as normal.
If it is higher or lower, the segments are marked accordingly.
To determine this:
The observed levels are compared to
the historical average, and
the historically observed range (the standard deviation - σ - around the average)
Currently, we use (see key in the bottom right):
Inside ±4σ → considered the normal range
Beyond ±8σ → described as very high or very low
Update frequency and smoothing:
This layer uses quarterly traffic data and is updated every 15 minutes
To reduce noise from short-term variations, we calculate a weighted average of the last 4 quarters
Weights: 8, 4, 2, 1, going back in time (with the most recent quarter weighted highest)
These parameters are subject to refinement as the system evolves
What this layer can show you:
It shows how busy a segment is in relative terms, i.e.
how current traffic compares to what it has been during the last 3 months.Example:
If a street suddenly becomes one-way and loses half of its traffic, it will appear as a very low traffic segment for a while, until the new traffic level becomes the new normal over the next few months.
What this layer cannot show you:
This layer does not show absolute traffic volumes.
For instance:
A segment that is always busy during the morning peak will still appear as normal, because that level of traffic is the expected norm.
To see absolute volumes, you still need to look at the Live traffic layer.
