Family of A9 car crash victims tell of shock The family of a mother and her daughter killed in a horror road smash - which also left the father and the girl's sister seriously injured in hospital - have told how they were "finding it incredibly difficult to describe the loss that we are feeling." Lawyer Andrew Houston, 42, lost his wife, Abigail, also 42, and seven-year-old daughter Mia in the Tuesday's tragedy on the notorious A9, between Inverness and Perth. The victims, from the Trinity area of Edinburgh, have been officially named by police. In a statement issued through Police Scotland, relatives said: "It is incredibly difficult to find the words to express the loss that we are feeling. Abigail was such a bright and vivacious woman who lived life to the full, adored her family and was greatly fulfilled through her work as a Paediatric Occupational Therapist. Mia was a delightful and beautiful little girl who enjoyed school and activities but most of all loved her family and friends. We ask that our privacy be respected so that we can focus on the recuperation of Mia's sister and come to terms with our loss in peace. The family were believed to have been travelling north to start their summer holidays. A man thought to be a German tourist who was travelling in the other vehicle was pronounced dead at the scene while his wife was also rushed to Raigmore Hospital in Inverness along with Mr Houston and his other daughter, Lily. Accidents Meanwhile, Chief Superintendent David O'Connor has called for a speed-up plans to make the road a full dual carriageway. He said there are "few roads in Scotland that have the same reputation as a dangerous road," and also suggested increased police patrols and a zero tolerance approach to illegal driving on the A9, such as speeding. He said he regularly drives on the road and that accidents occur on it with a "depressing frequency." Mr O'Connor added: "A major part of the problem is engineering, a lack of dual carriageway. The road needs to be dual carriageway for its entirety. While I welcome the Scottish Government position that work on making the A9 dual carriageway from Perth to Inverness will start early, in 2015 -2016, I have to ask: is this early enough? There have been other major capital investments made across Scotland for sound economic reasons. However, people are continuing to die and be seriously injured on the A9 with depressing frequency. Is this the case in some of the other projects? This needs to be looked at with fresh eyes and explored to see if it can be given a higher priority. Our elected representatives in the Scottish Government and Scottish Parliament need to ask themselves if they need to reassess their priorities and bring forward improvement work as soon as possible and not in 2015 or 2016 as is currently planned. Perhaps the time has come to not only significantly increase the police enforcement activity specifically on the A9 but also adopt zero tolerance to unlawful driver conduct in order to save lives. There may be other legislative measures to improve safety that can also be explored. I also believe that increased highly visible police patrols of the A9 can help prevent road collisions and the death and serious injury that frequently arise. Upgrade The Scottish Government's infrastructure and investment plan includes the upgrading of the road to dual carriageway by 2025 as most of the A9 is just single carriageway. The £3 billion work would convert 80 miles of the route. The accident, believed to have been a head-on smash between the Houston's Audi and a German-registered Jeep, happened on Tuesday evening on a single-carriageway section of the trunk road, south of Ralia, between Newtonmore and Kingussie. The A9 has claimed more lives between 2006-2010 than any other road in Scotland, with a figure of 67. There were 1026 accidents, an average of 200 a year. Transport Minister Keith Brown said: "Our deepest sympathies go to the relatives and friends of those involved in this week's tragic accident on the A9. Dualling of the A9 has been talked about for a generation or more, but this administration is the first to ever commit to making the road dual carriageway all the way from Perth to Inverness. This is one of the top transport infrastructure projects in the country - and we have already spent around £50 million pounds to improve safety on the A9 since 2007. We are determined that A9 motorists should see improvements on the route as soon as possible. We are now inviting bidders for three major design contracts for the route, and we will look for any opportunity to bring work forward.