Transport minister Lam Sai-hung said on Monday that officials will have to think very carefully before allowing cars from Guangdong and Macau into Hong Kong's crowded urban streets.

From early next year, people from the two regions will be able to drive into the SAR, but will have to park their vehicles at the end of the Hong Kong-Zhuhai-Macau bridge.

A second phase of the scheme was meant to let drivers take their cars directly into the city – similar to how the northbound part of the scheme allows Hong Kong vehicles to travel anywhere within Guangdong.

But Lam told an RTHK programme that officials need to carefully consider whether the second phase is plausible.

"Hong Kong's really small. And we all know our tourist areas in Tsim Sha Tsui, or both sides of Victoria Harbour, parking there is really an issue," he said.

"So we have to consider in detail what the arrangements are for cars coming from the mainland and Macau, whether limitations are necessary or something like that. We have to also look at Hong Kong's actual situation."