A user wants to generate a detailed analysis of how autonomous delivery drones might change city infrastructure. They use the following instruction:

'You are an expert in city planning. Explain the potential impact of autonomous delivery drones on urban infrastructure.'

Critique the effectiveness of the persona ('an expert in city planning') in this instruction. Then, propose specific, detailed improvements to this persona to elicit a more specialized and insightful response. Justify why your proposed changes would lead to a higher-quality answer.