Highways Agency - Safe roads, Reliable journeys, Informed travellers

Data Collected

2.1 The Traffic Impact Study (TIS) for the A10 Wadesmill, High Cross and Colliers End Bypass included the following surveys:

'Before' Surveys

• Traffic data from 12 Hertfordshire County Council permanent traffic count sites on County roads, 4 of which undertake continuous monitoring with the remaining 8 monitoring for one week per year in June;
• Traffic data from 3 Highways Agency permanent traffic count site locations;
• Nine temporary Automatic Traffic Count (ATC) surveys (tubes), five of which were conducted by Hertfordshire County Council, with the remaining four organised by Atkins;
• Manual turning count data on two junctions on the A10; and
• Journey time surveys undertaken in June 2002 on the existing A10 route from the roundabout with A120 towards Standon Hill to the intersection with the A1170.

'After' Surveys

For the Traffic Impact 'After' study it was not considered necessary to replicate all of the counts in the extensive programme conducted for the 'Before' study, and therefore a more appropriate count programme was adopted for this report. This report provides an initial assessment of the impact of the bypass in the immediate two months after opening. A more comprehensive comparison of all count sites assessed in the 'Before' study will be conducted for the 'One Year After' Study which provides a more in depth analysis of the impacts of the scheme;

• Seven temporary Automatic Traffic Count tube surveys, five of which were conducted by Hertfordshire County Council, with the remaining two organised by Atkins;
• Traffic data from 3 Highways Agency permanent traffic count site locations which includes one additional Highways Agency permanent ATC site on the new A10 Wadesmill, High Cross and Colliers End Bypass;
• Manual turning count data for two junctions on the A10; and
• The same journey survey route on the A10 was re-surveyed, in November 2004, with an additional journey time survey route via the new bypass.

2.2 The details of the 'Before' and 'After' surveys used in the TIS are described below, and illustrated in Figure 2.1 overleaf.

Figure 2.1 - Traffic Impact Study Count Sites (JPG 227KB)

Traffic Count Sites

2.3 Figure 2.1 shows the locations of the count sites surveyed for comparison in the Traffic Impact Study.

Automatic Traffic Counts

2.4 There were 2 Highways Agency permanent ATC sites located on the existing A10, plus the one installed on the A10 bypass. For the 'Before' surveys these sites counted for a period of 4 weeks during June 2003, and similarly, for the 'After' survey data a four week period was collected from 11th October. The locations are as follows:

• A10, North of Puckeridge and before Hay Street;
• A10, South of Ware; and
• A10 Wadesmill, High Cross and Colliers End Bypass.

2.5 Two temporary ATC sites were placed by Paul Castle Consultancy to the South of the bypass, and these were located on the:

• A10 between A602 junction and Moles Interchange; and
• A1170 between Quincey Road and Moles Interchange.

2.6 There were five temporary tube sites installed by Hertfordshire County Council on five local feeder roads to the A10 around Wadesmill, High Cross and Colliers End. For the 'Before' surveys the sites were surveyed for three weeks in October 2003, and for the 'After' surveys two weeks between 1st November 2004 until the 14th November was collected. The locations are as follows:

• East of the A10 on Cold Christmas Lane, Thundridge;
• West of the A10 on Barwick Lane, Standon Green;
• East of the A10 at Barwick Lane, Barwick;
• East of the A10 on Dowsetts Lane, Colliers End; and
• West of the A10 on Old Hall Green Lane, Puckeridge.

2.7 There were 4 Hertfordshire County Council permanent ATC sites with continuous data which were used for the study. For the 'Before' surveys three of these sites counted for a period of 4 weeks during June 2003 with one counting during April 2003. The 'After' survey data was collected for two weeks between 1st November to 14th November. These locations are as follows:

• A1184 Cambridge Road at Sawbridgeworth;
• A414 Eastwick Road, West of Harlow;
• A602 at Bragbury End, near Stevenage; and
• B1368 at Dassels Hill, Hay Street.

Manual Classified Counts

2.8 Manual Classified Counts were conducted at two sites for a 12 hour period between 07:00 and 19:00. These were at:

• A10/Standon Hill, which included additionally the A10 Bypass in the 'After' study; and
• A10/B158 Anchor Lane.

2.9 The 'Before' counts were conducted on the 20th June 2002 with the 'After' counts being conducted on the 2nd November. Vehicles were classified into car, van, other goods vehicles 1 (OGV1), other goods vehicles 2 (OGV2) and bus.

Journey Time Surveys

2.10 Journey time surveys were undertaken on two routes, identified as 'Red' and 'Blue' routes, which are illustrated in Figure 2.2. The 'Red' route represents the existing route through Wadesmill, High Cross and Colliers End, from A120 Standon Hill/A10 roundabout to A1170/A10 intersection. The 'Blue' route is the length of the new bypass. 'Before' journey time surveys previously conducted on Thursday 20th June were used for comparison with surveys post scheme opening on Tuesday 2nd November. The surveys were undertaken over the AM peak (0730-0900 hours), PM peak (1700-1900 hours) and an inter-peak period (1000-1130 hours).

Figure 2.2 - Journey Time Survey Routes (JPG 412KB)