The National Party is promising to spend a $9 billion over 10 years upgrading roads, if re-elected.
Major roads that could be upgraded include the road linking Waikato and Tauranga, SH1 from Cambridge to Tirau, the Hawke's Bay expressway and SH1 north and south of Christchurch.
National's transport spokesperson, Steven Joyce, says his party's approach is balanced and includes a commitment to public transport.
The Green Party says the spending doesn't make sense and it would be better to spend more money on public transport. Transport spokeperson Gareth Hughes says the party is supporting a rail loop project for central Auckland, which he says would reduce traffic congestion and benefit the whole region.
Mr Joyce does not support the rail loop and says not enough people will switch from private cars to rail to make it cost-effective.