A speed camera van recorded 105 motorists speeding on Ocean Drive in Leith over just four hours. Some were doing under 30mph and others more than 40mph.
Police said they would receive fixed-penalty £100 fines and three penalty points on their licence, or be reported for prosecution.
It came at the start of a three-month deployment of mobile speed camera vans in the street beside Leith docks.
This is the first significant operation to enforce the city-wide 20mph limit, which was completed last year. Fixed speed cameras are not currently calibrated to detect speeds below 30mph.
The speeders were caught during two two-hour deployments last week.
Andy Jones, east area safety camera unit manager for Police Scotland, said: “We won’t disclose the full range of speeds, however a number of offences were over 30mph and a minority were recorded in excess of 40mph.
“The high number of offences is somewhat disappointing, as we published our enforcement intentions. The results reinforce the local community, community council and council’s concerns.
“We will continue to undertake robust enforcement at this location, ensuring the safety of all road users.
“I hope to see a significant reduction in speeding offences at this location and ask everyone plays their part by adhering to the posted speed limit.”
Neil Greig, policy and research director of motoring group IAM RoadSmart, said: “We are disappointed but not surprised to see such high numbers.
“They highlight the complete failure of the blanket 20mph speed limit approach to remind drivers a road that doesn’t look unsafe is still covered by a 20mph speed limit.
“Ocean Drive looks and feels like a wide, free-running road with relatively few pedestrian crossing away from junctions.
“Police Scotland risk losing public support for 20mph by choosing to enforce on such roads.”
City council transport convener Lesley Macinnes, said: “20mph speed limits have been set on Ocean Drive and across the city for a reason – to create a safer environment, particularly for more vulnerable road users, and to encourage a calmer, more relaxing atmosphere – so it’s disappointing to see a number of people flouting this.”