Outpatients attending the new Children's Hospital will be encouraged to use public transport instead of their cars.
Hospital staff will be forced to leave their cars at home and use alternative transport to work due to a reduction of 224 in the number of staff parking spaces, according to the designers of the new facility.
Staff parking is currently free, but an annual charge of €500 will be imposed.
Transport engineer Donal McDaid said the cut in staff spaces would encourage the 3,200 people employed at the Children's Hospital and the 4,000 at St James's to use "public transport, cycling and walking".
The 675 public parking spaces would be prioritised for patients and families of patients who needed to travel by car, and spaces could be pre-booked.
Those making out-patient appointments would be encouraged "to arrive by alternative modes where possible".
There are only 230 public spaces between the three existing children's hospitals.
Mr McDaid, the engineer responsible for the transport strategy for the new hospital, said staff who cycled could use new dedicated showers, lockers and changing facilities.
Proposals for the new hospital on St James's Hospital campus are being examined. It would replace the existing hospitals at Temple Street, Crumlin and Tallaght.
Structural engineer Paul Healy, for the National Paediatric Hospital Development Board (NPHDB), rejected calls from neighbours to curtail construction hours, saying that to cut the working time by a single hour a day would add two to three months to the building phase.
Mr Healy stressed that the development team would carry out surveys of all homes in the vibration risk zone before and after construction, which was expected to take about 46 months.
A specialist consultant was being appointed for detailed monitoring of all vibration during excavation works, said Mr Healy.
He added that it was proposed to carry out works from 7am to 7pm from Monday to Friday and 8am to 2pm on Saturdays. There would be no work on Sundays.