Technical surveys
Recognise
For the Smart Motorway Programme (SMP) Tranche 5 (TMTii38) and Tranche 6 (TMTii46) technical surveys, the concept of increasing survey productivity in a single shift was considered, researched and promoted. The approach was based on capturing all highways asset data in one shift covering 4km. This included drainage, topographical (site clearing), coring, and deflectograph surveys. This approach would have safety, customer and delivery benefits.
Define
Purpose
To increase productivity when undertaking technical surveys for Smart Motorway Projects.
Deliverables
Increased productivity for technical surveys
Stakeholder benefits
Carnell: increased productivity making better use of our resources.
National Highways: efficiency savings contributing to KPI
target; quicker access to asset information to allow more effective decision making.
Customer: reduced roadworks bringing increased journey time reliability.
MP Designer: faster survey information to inform the design process bringing design programme time savings.
Success criteria
Efficiency savings calculated and delivered.
The following sections of the highways network were surveyed using this approach:
SMP Tranche 5
- M25 Junction 10-16 (24.1 km) – April 2018
- M62 Junction 20-25 (31.9 km) – January 2018
- M40/M42 Interchange (11.5 km) – March 2018
- A1 Junction 6-8 (13.4 km) – February 2018
SMP Tranche 6
- M1 J35a-J39 (22.2 km) – September 2018
- M1 J19-J23a (54.0 km) – August 2018
- M42 J0-J3 & M5 J4A-J4 (17.7 km) – August/September 2018
Measure
With a conventional drainage survey, we would use 2 survey teams (2 x CCTV, 2 x GPS, 2 x Jetting Units), and these generally cover 800 – 1000m a shift.
Both carriageways of the scheme length need to be surveyed i.e. two verge lengths and one central reservation length. As an example, the M25 Junction 10-16 was 24.1km (24,100m) in length, so total survey length for both verges and central reservation would be 24,100 x 3 = 72,300m. Based on the conventional survey approach of c.1000m per shift using 2 survey teams this would take 72,300/1000 = 72 shifts.
Analyse
We analysed the existing conventional approach and identified process waste within the survey value stream using TIM WOODS to pin-point waste.
Transportation
The existing approach has unnecessary transportation of equipment, tools and people to/from site through not maximising work within single closures, therefore requiring more closures overall. This unnecessary transportation also leads to increased fuel usage and increased wear and tear on equipment.
Inventory
The existing approach sees a longer lag time on inventory (survey data) before this is processed and available for design teams (customers) to progress design work i.e. the inventory sits with us for longer than it has to.
Waiting
Waiting to complete survey data, with less productivity per shift based on less survey teams and equipment than could be accommodated within the footprint of the traffic management closures. Ultimately leads to longer time for product to reach customers.
Skills
By using less survey teams, we have spare capacity, or non-utilised talent (skills) i.e. we can increase our utilisation of owned or hired people and equipment by maximising use within traffic management closures.
Improve
The smart approach using multiple survey teams enabled 4000m to be surveyed each shift making effective use of traffic management, so on the example survey on the M25 Junction 10-16 survey length of 24.1km, the shifts needed were:
Clockwise verge: 24100/4000 = 6 shifts (using 8 x CCTV, 4 x Jetting Units, 4 x GPS)
Anti-clockwise verge: 24100/4000 = 6 shifts (using 8 x CCTV, 4 x Jetting Units, 4 x GPS)
Central reservation: 24100/4000 = 6 shifts (using 8 x CCTV, 4 x Jetting Units, 4 x GPS)
This equates to a total of 18 shifts.
The shift saving (conventional to smart) is 72-18 = 54 shifts.
The efficiency saving is the cost of saving 54 shifts of traffic management minus the additional cost of increased survey resource each shift.
Control
This lean intervention has been controlled by ensuring we retain and maintain the resource capacity to deliver this approach in the future, where multiple survey teams and units are required.
We have shared the approach with our Water Management Division to ensure that where opportunities arise in the future, this multi-benefit lean approach can be promoted to clients.
Transfer
This improvement has been highlighted across the wider Smart Motorway Programme by the teams involved.
The National Highways Efficiencies (Commercial Intelligence) Team involved in assuring the Efficiency value as part of National Highways' RIS1 KPI target advised that “this efficiency will be added to our list of top efficiencies and redistributed to all schemes, PELs and through the monthly efficiency updates".
Benefit summary
Resources: Although the new approach required an increase in resource capacity for a single shift i.e. additional survey teams, jetting units, CCTV units, and GPS equipment, Carnell had access to the enhanced resource levels which enabled increased utilisation of plant and equipment.
Efficiency saving: Based on the estimated 54 shifts saved on the M25 Junction 10-16 scheme, and projecting this saving over the other six sections surveying using this lean approach, it is estimated that an efficiency saving of £1,638,086 has been generated. This efficiency saving was reviewed and assured by National Highways Efficiency (Commercial Intelligence) Team.
Customer experience: The new approach delivered a 75% reduction in the number of shifts required to complete the survey work. That represents a 75% reduction in the number of traffic management closures required. In total across the 7 sections, it is estimated that this approach saved 392 shifts of traffic management and therefore 392 nights of disruption for customers. Using webtris daily traffic flow data, it is estimated that this approach has resulted in 6.5 million customers (road-users) not experiencing roadworks (based on traffic flows between 20:00 and 06:00hrs). This makes a significant contribution to improving customer satisfaction, firstly through less roadworks, and secondly by customers being able to observe more work being done in each roadworks closure i.e. when they do pass roadworks, they can see plenty of activity taking place.
Design: The SMP design teams were able to access survey information faster, allowing designs to be completed in less time, and avoiding the risk of any abortive design work based on assumptions rather than technical survey data.