New regulations banning trucks on urban roads during peak hours could trigger a spike in the cost of essential goods.

Transport Minister Dipuo Peters has signalled her intention to introduce amendments to the National Road Traffic Regulations of 2000, which will see trucks exceeding a gross vehicle mass of 9,000kg being banned from urban roads on weekdays between 6am and 9am and 5pm and 8pm.

The minister made this known in April last year and published draft regulations for public comment in May 2015.

The ministry cited congestion and the country’s high road mortality rate as the key drives for the proposed regulations.

However, Road Freight Association spokesman Gavin Kelly said consumers would bear the brunt of this as nearly 20% and 19% of the price of bread and milk, respectively, factored transport and logistics costs. Mr Kelly said companies would have to change their delivery schedules, many of which were planned months in advance and this would have cost implications.

"Some basic goods could see a 20% increase in a short time. The indirect costs are difficult to calculate, but it is clear there will be some," said Mr Kelly.

The association estimates that 80% of goods are moved by road.

In its public comment submission on the draft regulations, the Justice Project SA said that in an ideal world, the proposals would constitute a "no-brainer".

"Unfortunately, however, SA is not part of the ideal world, not even by a long shot," it said. "The majority of freight and goods on supermarket shelves are conveyed on our roads due to the fact the rail network has been so neglected and mismanaged by the Department of Transport for a long time now."

Trade Law Centre researcher JB Cronje said if the objective of the proposal was to alleviate congestion, then all vehicles — regardless of size — should be targeted.

Patricia Pillay, head of legal and regulatory affairs at the Consumer Goods Council, said there was no clear indication what penalties would be imposed on companies if their trucks were found on the road outside of set hours.

Ms Pillay also said that while the proposals were excellent, they would be difficult to enforce.

Department spokesman Ishmael Mnisi said he did not have progress details of the draft regulations at hand when he was contacted for comment.