A response from Mr Twyford's office stated those questions were "operational" in nature and had been passed on to the New Zealand Transport Agency to answer.
The response from a Transport Agency spokesman said the agency was investigating a package of safety improvements for SH50 between Napier and Hastings, as part of the Safe Roads programme.
He made no specific reference to a 4-lane expressway.
Speaking to Hawke's Bay Today, Mr Yule, a former Mayor of Hastings, yesterday said the change to the expressway was a "big deal" for both the National Party and for Hawke's Bay.
He added that the road was announced as part of the last government's roads of national significance funding package because it was already a designated road.
"All they have to do is construct it. The reason Hawke's Bay was chosen was because we are seeing a record level of growth and there was a ready project that was available to be funded that could be built.
"I'm particularly anxious about it because the latest Napier Port briefing shows that the volumes of cargo through Napier Port are going increase by 49 per cent by 2026, at the same time as there is a move to take traffic off Marine Parade."
That would result in an extra 95,000 truck movements a year by 2006.
"I think this project needs to be elevated in priority to deal with that growth or we are going to slow down the growth opportunities of the region.
"They don't need to build the expressway tomorrow but I want to make sure that actually it is elevated in priority for the region because there is already congestion at peak times.
"You start adding on those extra truck movements then there is going to have to be some pretty major upgrades to both the expressway and through Ahuriri."
Mr Yule said while the project had not been costed as an individual project, it was "vitally important" to the people of Hawke's Bay.
"So when they look at how they use their money on in Auckland transport and light rail - they need to remember that there are really big projects still in the regions that make a really big difference to the people of Hawke's Bay - and this is one of them."
Napier Mayor Bill Dalton also called on the government to commit to the much needed project.
"The situation is simply that it needs to get on the books because we're getting more and more people living in Napier and Hastings, all across Hawke's Bay and a lot more of those people are commuting from one city to another. They are working In Napier and living in Hastings, and vice-versa.
"We are going to need it and, in fact, if we don't get it on the books and commit it - absolutely commit it, then it will never happen and so I think it's important that the Government commits to it, even if it's in year four, five or seven in their long term plan - but they certainly need to commit to it."
Hastings Mayor Sandra Hazlehurst said she looked forward to discussing the region's transport needs, including the widening of SH50, with the Government.
"We have a number of transport investment priorities for the region including the Manawatu Gorge replacement, SH2 North improvements, resilience for SH5 and the expressway four-laning.
"Hastings District Council looks forward to discussing the priority of these projects with the Government as they develop the next National Land Transport Programme."
"It is great to hear Napier Port's expansion plans and it is vital we have the most effective regional transport network to support the region's strong economic growth."