A project has smaller parking on ground level in front of the building and larger parking underground. The project team is proposing allocating all above-ground level parking as preferred parking area (for Green vehicles and for car poolers).

Can preferred parking area be specified only with a signage (e.g. 'ONLY car-pool and fuel (CO2) efficient vehicles') at the entrance of the above ground parking area or is it still necessary to have all preferred parking spaces to have individual signage/marking?