Mae nifer o broblemau wedi cael eu nodi yn dilyn y gwaith o gasglu a dadansoddi gwybodaeth a data. Roedd y dystiolaeth a'r data a gasglwyd yn cynnwys arolygon geoffisegol, arolygon o fioamrywiaeth, cyfrifiadau traffig, dibynadwyedd amserau siwrneiau, darpariaeth trafnidiaeth gyhoeddus, data traffig tymhorol, data ar ddifrifoldeb damweiniau, data economaidd-gymdeithasol a chyfyngiadau amgylcheddol.
A number of problems have been identified following collection and analysis of information and data. The evidence and data collected included geophysical surveys, biodiversity surveys, traffic counts, journey time reliability, public transport provision, seasonality traffic data, accident severity data, socioeconomic data and environmental constraints.