Within a few months, a small consulting group from Asplan Viak and Rambøll has planned a corridor for the future four-lane E18 between Dørdal-Tvedestrand and Arendal-Grimstad, two stretches totaling 75 km. The state-owned road developer Nye Veier AS gave the engineers the task of preparing a municipal subplan before summer who then swiftly returned with optimal corridors for the road alignment.
The corridor alignment work is an important part of the planning program and will be a basis for decision making in the municipal subplan the consultants work on. Seven municipalities have entered into an inter-municipal planning cooperation, which aims at approving a municipal subplan for the new E18 roads by summer 2019.
Ambitious plan – exciting measures
“Nye Veier wants to make use of any new tool that can help streamline the planning process,” says Nye Veier's project manager Solfrid Førland. “The overall goal of the road project is to make it socioeconomically profitable. We believe model-based collaboration and open information flow contribute to success. Therefore, we will complete the road project through a full digital planning process, and we have contracted the consultants using the Best Value Procurement method to do that. In order to succeed with the project, it is important that all stakeholders are kept oriented on a regular basis and are given the opportunity to provide input.”
Automates the process
“Our startup challenge was that the municipal subplan had to be made in a very short period of time, compared to what is common for such plans,” says road discipline manager Venche Rørtveit at Rambøll. “Therefore, it became extra necessary to do the job as effectively as possible. Following an introduction to Trimble's Alignment Planning System Quantm, we found that this tool could make a significant contribution to streamlining the process, both time- and cost-wise.”
Trimble Quantm is a tool that analyzes the terrain and road obstacles in an area. The tool then automatically calculates all alternative corridors and compares thousands of different alignment alternatives to find the most optimal line – without manual calculations. The tool is particularly rewarding during the investigation phase, providing a comprehensive overview of all options – helping planners to identify all possible corridor alternatives and conflicts of interest – resulting in cheaper and better road alignments.
Two road stretches
For practical reasons, the consultants chose to divide the assignment into two. Lars Kastet and Håvard Nordaunet are Asplan Viak's road engineers on the task. They work on the E18 Arendal-Grimstad road corridor, a 20 km long stretch that mostly will go through inhabited areas. The planning of the 55 km long E18 Dørdal-Tvedestrand stretch, which mainly will pass through untouched nature, is done by road engineers Sissel Innhaug Dahl and Håvard Glosli at Rambøll. Both stretches have different challenges with regards to terrain and restrictions that require consensus.
From open to narrow searches
“In the beginning, we made open searches without any special restrictions,” explains Lars Kastet. “Only the terrain and average unit prices on the road, bridges and structures were entered into the system. In addition, general dimensioning parameters were set for the selected road class. This provided a rough overview of alternative corridors, ranging from expensive to cheap alignment options.”
“Then we have filled the model with all kinds of information about priced areas, areas to avoid, tunnels, and how to cross rivers and water – entered more and more information. The model has this way gradually become more detailed and the corridor searches more and more precise and optimal.”
Optimizes line selection
“What is particularly useful with Quantm is that we get the cost element included right from the start,” adds Sissel Innhaug Dahl, who has worked on the long stretch between Dørdal and Tvedestrand. “Most projects are obviously driven by costs. Here you get prices included right away and may compare the line alternatives on equal terms.”
“We have therefore focused on the alternatives that have appeared most promising and tried to avoid areas that are likely to lead to objections. We early on included areas that were to be avoided, typically protected areas, cultural sites, nature conservation areas and agricultural areas of regional-national value.”
“We have done many searches with Quantm,” adds Håvard Glosli. “55 km is a long stretch. The tool has been of great help this early in the process. As the project is very cost-driven we can avoid problematic areas from the very start and take measures already now to reduce costs.”
Anchoring the process
“The consultants have operated with four phases to anchor the work among the stakeholders,” explains project manager Førland. “At regular intervals, we have had checkpoint assessments and made decisions to ensure that we have been on the right track. All tools must be supplemented with professional assessments. For instance, were Phase 1 and 2 presented at a public meeting, with all the lines that were relevant at that time. We were a little skeptical about this, but it actually turned out good. We can now better answer questions about the line choices in retrospect.”
“The result so far is no single road line, but a recommended road corridor that the governing bodies will address and decide on during the autumn,” says Håvard Nordaunet.
“The corridor, which was quite wide at the beginning, has gradually become narrower. The goal is that, when the municipal subplan is completed, we will have a corridor that is a few hundred meters wide, forming the basis for a zoning plan in the next phase.”
Not possible manually
“You can assess many corridors in a short period of time and get a good overview of the area and different lines,” continues Lars Kastet. “In a few hours, Quantm can find hundreds of line options, which of course is impossible manually. The tool has been of great help, not least also to eliminate alternatives and to bring forward alternatives that otherwise would not have been thought of. It is very effective.”
Uncovers conflicts of interest
“The tool also shows clearly when some ´eggs need to be crushed´ to find space for the new road,” says Nordaunet. “When it, at one point of time, did not find a single relevant corridor, we quickly realized that the restrictions imposed were simply too big. Some restrictions have then to be altered or eliminated. Especially on Arendal-Grimstad there are many domains and conflicting interest disagreements – which consequently have to be assessed and evaluated in the planning work.”
Professional assessments important
“For Nye Veier´s part it is important that we always supplement the tool with professional assessments – which the consultants have been good at in this case. You don´t get more out of a tool than you put in. The combination contributes to ensuring a good choice of corridor,” adding Førland.
“We are now much more confident that we have found good corridor alignments, than by doing the work the old way,” Sissel Innhaug Dahl adds. “Now we have very solid reasoning for why we have proposed the corridor area we have chosen. In addition, we can much more confidently answer why other line alternatives are not included. We simply check them out in Quantm and are able to provide clear answers. The rational is most often too high costs.”
Analysis and management tool
“By utilizing the tool right from the start, we can take the right socioeconomic considerations as well as take into account individual interests, from day one. By gaining early insight into all options and conflicts of interest, we can now take the right considerations in an early phase – at a time when we have the opportunity to actually do something about it,” says Håvard Glosli.
“Nye Veier's main focus is as stated to carry out a cost-effective road project socioeconomically. What we are doing here is both exciting and promising in that respect. We have strong faith in this,” concludes Solfrid Førland.