As towns were developed according to the Buchanan blueprint, several issues emerged.

Some of the grand plans that were called for have had a poor reputation in their implementation; to be able to predict future trends, mix social development, transport skills, and economic regeneration while performing slum clearance has often been beyond the capability of the local planners.
Public accountability required by local government officers was sometimes stretched, with accusations of corruption involving private sector developers and contractors who put the plans into action.
The cost inflation of schemes conspired with fluctuation of the property market, and its subsequent collapse in the early 1970s, left many plans incomplete.
When economic conditions improved conservation had once again become fashionable and confidence in the need for these centrally-controlled grand plans had evaporated.

The courage needed to develop the schemes required a lot of political will, and that would sometimes falter.
By failing to identify cheaper alternatives when the financial case weakened, "do-nothing" often became the default action.
For example, the extensive plans to develop a series of orbital and distribution roads into central London resulted in the construction of the A40(M) Westway, the M41 cross route and A102(M) Blackwall tunnel.
However, the wide impact of these schemes caused such controversy during the 1970s that many associated road schemes ran into concerted opposition.
After the 1973 oil crisis, remaining schemes fell into limbo, casting a planning blight over the affected areas for a decade or more until they were finally laid to rest.
 The recognition of environmental factors was also lacking in the 1960s; the report's considerations were more about the human environment, rather than the natural issues which have tended to confound some subsequent road proposals.

More latterly, the policy has been accused as being one of "predict and provide", or of building new roads in a congested network that generate even more traffic, rather than just meeting existing demand.
This is to partly misrepresent the policy recommendations; although neither traffic generation and the deterrent effect of congestion, nor the mechanisms by which a business would choose to (re-)locate his premises was understood at the time, the report strove to strike a balance for situations when capacity demands could not or should not be met.
Buchanan later claimed that radical urban surgery was almost the opposite of what he was proposing:
...in spite of all the effort, it was widely misinterpreted … the Report was a description of the choices open, from 'do nothing to whole hog', with the advantages and disadvantages set out.

In some schemes, the separation of different types of road users would often be taken to extremes: by moving motor vehicles onto dedicated routes, their interaction with pedestrians or cycle routes might occur less often but would do so at higher speeds than before, thus creating an environment that was far more hazardous or intimidating for those not in cars.
New towns like Milton Keynes could avoid this by placing motorists, cyclists, and pedestrians on separate levels and routes.
However, their interaction would be a particular problem in established towns, especially in the transition to suburban areas where separation would be more ambiguous and inconsistent.
In the search for low traffic casualty rates, urban planners now look to detailed road designs and traffic calming to counteract this effect, reducing vehicle speeds, or taking the more dramatic step of eliminating separation and mixing all road users together through shared space planning.

At the heart of many of the new schemes was architecture of poor quality or poor design, and a poor understanding of the effects of the new road network.
As warned by Buchanan, the detailed implementation of many of these schemes critically affected their success or failure.
Subsequent research has shown that more is needed than a pedestrian centre with glass shop fronts, accompanied by
As towns were developed according to the Buchanan blueprint, several issues emerged.
Some of the grand plans that were called for have had a poor reputation in their implementation; to be able to predict future trends, mix social development, transport skills, and economic regeneration while performing slum clearance has often been beyond the capability of the local planners. Public accountability required by local government officers was sometimes stretched, with accusations of corruption involving private sector developers and contractors who put the plans into action. The cost inflation of schemes conspired with fluctuation of the property market, and its subsequent collapse in the early 1970s, left many plans incomplete. When economic conditions improved conservation had once again become fashionable and confidence in the need for these centrally-controlled grand plans had evaporated.
The courage needed to develop the schemes required a lot of political will, and that would sometimes falter. By failing to identify cheaper alternatives when the financial case weakened, "do-nothing" often became the default action. For example, the extensive plans to develop a series of orbital and distribution roads into central London resulted in the construction of the A40(M) Westway, the M41 cross route and A102(M) Blackwall tunnel. However, the wide impact of these schemes caused such controversy during the 1970s that many associated road schemes ran into concerted opposition. After the 1973 oil crisis, remaining schemes fell into limbo, casting a planning blight over the affected areas for a decade or more until they were finally laid to rest.  The recognition of environmental factors was also lacking in the 1960s; the report's considerations were more about the human environment, rather than the natural issues which have tended to confound some subsequent road proposals.
More latterly, the policy has been accused as being one of "predict and provide", or of building new roads in a congested network that generate even more traffic, rather than just meeting existing demand. This is to partly misrepresent the policy recommendations; although neither traffic generation and the deterrent effect of congestion, nor the mechanisms by which a business would choose to (re-)locate his premises was understood at the time, the report strove to strike a balance for situations when capacity demands could not or should not be met. Buchanan later claimed that radical urban surgery was almost the opposite of what he was proposing:
...in spite of all the effort, it was widely misinterpreted … the Report was a description of the choices open, from 'do nothing to whole hog', with the advantages and disadvantages set out.
In some schemes, the separation of different types of road users would often be taken to extremes: by moving motor vehicles onto dedicated routes, their interaction with pedestrians or cycle routes might occur less often but would do so at higher speeds than before, thus creating an environment that was far more hazardous or intimidating for those not in cars. New towns like Milton Keynes could avoid this by placing motorists, cyclists, and pedestrians on separate levels and routes. However, their interaction would be a particular problem in established towns, especially in the transition to suburban areas where separation would be more ambiguous and inconsistent. In the search for low traffic casualty rates, urban planners now look to detailed road designs and traffic calming to counteract this effect, reducing vehicle speeds, or taking the more dramatic step of eliminating separation and mixing all road users together through shared space planning.
At the heart of many of the new schemes was architecture of poor quality or poor design, and a poor understanding of the effects of the new road network. As warned by Buchanan, the detailed implementation of many of these schemes critically affected their success or failure. Subsequent research has shown that more is needed than a pedestrian centre with glass shop fronts, accompanied by
Traffic in Towns