Only five out of about 80 Dunedin schools assessed for traffic problems could get 40kmh speed zones outside their gates.
The five schools were the only ones that met New Zealand Transport Agency criteria for speed reductions during peak traffic times.
The 40kmh variable speed limits and a range of speed cuts on 12 roads in Dunedin will be put out for public consultation as part of a proposed bylaw amendment, if approved at a planning and regulatory committee meeting on Tuesday.
In New South Wales, every school has a 40kmh speed zone.
But council senior traffic engineer Ron Minnema said New Zealand legislation had no provision to make such widespread changes.
The schools were assessed to determine if they qualified for a 40kmh variable speed limit to reduce the risk to vulnerable road users, he said in a report to the committee.
The five schools were Carisbrook School, King's High School, Queen's High School, Kaikorai Valley College and Wakari School.
Criteria included how many children walked, cycled, entered or exited vehicles along a school road; the speed limit on the road; if it was a main route; if there had been any accidents; and if physical constraints obscured lines of sight.
Some of the schools had excessive speed of traffic outside their gates while others had had accidents at peak times.
Carisbrook School principal Ben Sincock said the school ''desperately'' needed a lower speed limit on South Rd.
''We have major concerns about the safety of students on that road,'' Mr Sincock said.
''Even though there is a pedestrian crossing, it is still a very risky prospect.''
Traffic was ''incredibly fast'' and even with the crossing manned there were close calls as cars failed to slow down or stop, he said.
On Bay View Rd, outside King's and Queen's High Schools, there had been 10 reported accidents, one immediately before and three immediately after school hours. One had involved a pedestrian.
Outside Kaikorai Valley College, there had been two accidents on Kaikorai Valley Rd, one immediately before and one immediately after school hours.
Mr Minnema said other schools which had not met the criteria had been found to require safety measures such as signs, guard rails or centre lines.
''Every school is unique and we tailor what we do to each situation and a 40kmh variable may not benefit other schools.''
A problem facing many schools was congestion. Traffic was already travelling below 40kmh and other measures were needed.
If the bylaw change was approved, the council would put up variable speed signs in the five school zones at a cost of about $65,000.
It would come out of the 2014-15 minor improvements budget subsidised by the transport agency.
The School Traffic Safety Group, which has representatives from schools, police, city council and the New Zealand Transport Agency, had been advised.
If approved by the committee, the variable speed changes could form part of a speed limit bylaw amendment to be considered.
School variable speeds
• Carisbrook School, South Rd (Eastbourne St to Surrey St) 8.30am to 9am, 3pm to 3.30pm.
• King's High School and Queen's High School, Bay View Rd (Surrey St to Moreau St) 8.30am to 8.45am to 2.55pm to 3.10pm.
• Kaikorai Valley College, Kaikorai Valley Rd (Bryant St to Salisbury St) 8.15am to 8.35am, 2.55pm to 3.10pm.
• Wakari School, Helensburgh Rd (Shetland St to Mayfield St) 8.40am to 9am, 3pm to 3.15pm.
Estimated cost: $65,000 for 40kmh variable speed limit signs.
