The survey conducted by the Barbican showed that planners were also unhappy about changing transport as part of their travel arrangements, with 64% saying they would change a maximum of twice.
More than half (53%) of respondents in the poll described themselves as corporate bookers, while 21% said they were association and 26% agency.
The Barbican said the results demonstrated the importance of high speed travel infrastructure projects such as HS2 and the Elizabeth Line.
Barbican head of events Jackie Boughton said: "It is no surprise that organisers want to minimise travel time but keeping it to less than an hour is tough, even for many commuters.
"It is clear from these results that delegates want to focus on productivity and work rather than logistics and travel. Organisers need to juggle the appeal of each venue and its surrounding infrastructure and opportunities with ease of travel."
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