PJA was commissioned by Crediton Town Council to develop a VISSIM model of the local highway network, to assist with an air quality assessment relating to urban realm improvements on the High Street. Traffic data from the with scheme model will be used as an input for detailed air quality modelling undertaken by the town council’s retained air quality consultants.
The VISSIM modelling is informed by an urban realm feasibility study produced by PJA in November 2018. The report tabled proposals seeking to improve pedestrian conditions and deliver better urban realm in the town.
A VISSIM model was constructed on the High Street between St Boniface Road and Four Mills Lane, which included AM and PM peak periods. The model was built using static traffic assignment, as there is no element of route choice, and allows the assessment of future schemes to be assessed more efficiently.
As a significant level of informal crossing was observed around the central High Street area, it was necessary to use VisWALK to simulate the more dynamic nature of pedestrian movements in this location. Bespoke conflict area behaviour was used to replicate the proximity pedestrian interactions present on the High Street. The model also uses dynamic parking to replicate the delays incurred by vehicles parking on the narrow high street.
The VISSIM modelling allowed an iterative process to the traffic engineering to be adopted, with delays incurred by specific elements of the scheme identified and revisions to the design made if required.
PJA produced videos, providing a visual representation of the proposed scheme, as well as traffic and air quality data.
