Isle of Wight Council bosses have overturned a vote by councillors - who had rejected the partnership to secure £900 million of funding.
New Dorset Police Chief Constable Chosen
Acting Chief Constable Debbie Simpson has been chosen as the new head of the Dorset force.
She will take over from Martin Baker who stepped down last year.
The decision will be confirmed next month.
Speaking after the announcement Police and Crime Commissioner Martyn Underhill said: "I am delighted to propose Debbie Simpson as the next Chief Constable of Dorset.
"This was a unanimous decision by the Panel. There was a strong range of candidates and the panel had a difficult job. I would like to thank all the candidates for their interest."
The busy road's being made two lanes in both directions between Segensworth and Titchfield - it's due to take 18 months.
Police want to trace man after 11-Year-Old Approached Near Oasis Academy
Family Appeal Is Shared Online After 14-Year-Old Missing Since Friday
Recently Played Tracks
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
What's happening on the roads where you are?
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.
Find out more about some of the companies advertising on Heart.
Get some great ideas on how to advertise your business on radio, online and on mobile.