7.1Site selection#
The general considerations when choosing a suitable site location are:
- safety
- visibility
- geometry, such as horizontal curvatures, vertical curvatures, longitudinal grade, and lane width
- risk of flooding
- security
- comfort
- cabinet location, and
- pavement condition.
In addition, the site and pavement characteristics in the vicinity of the sensors influence road users' behaviour and, hence, can affect the quality of data. It is important when selecting a site location that these considerations are thoroughly assessed as they will compromise data quality.
Although it may not always be possible to satisfy all the preferable site features, designers shall demonstrate that all effort has been made to minimise the risk of data inaccuracy and inconsistency resulting from unfavourable site locations and characteristics.
Listed following are the characteristics that a site should avoid:
- sites that have bad lane discipline and excessive lane changing
- sites where vehicles will not cross perpendicularly to the piezo or tube sensors
- sites where vehicles accelerate or decelerate due to geometry, traffic signals, or intersections
- sites where vehicles stop or park on / over sensors of the site, and/or
- sites where vehicles will turn