The assembly's congestion charging scrutiny committee is examining the feasibility of London mayor Ken Livingstone's charging proposals, and his plan to have them in place by the end of 2002.
Liberal Democrat chair Lynne Featherstone said: 'There are concerns over the effects the policy will have outside the charging zone. We don't want traffic displaced from this area causing chaos in other parts of London.'
Her committee will hear from expert witnesses, including the AA and the DETR. It will not judge the wider political debate on charging, opposed by many Conservatives.
The office feels congestion charging is a matter for the mayor and assembly. Though officials will answer queries in writing, they will not give views on proposals.