Highways Agency

• A11 roudham heath - attleborough improvements
• A11 roudham heath - attleborough improvements Introduction
• A11 roudham heath - attleborough improvements Data collected
• A11 roudham heath - attleborough improvements Summary of results
• A11 roudham heath - attleborough improvements Conclusions
• A11 roudham heath - attleborough improvements Annex A

A11 Roudham Heath to Attleborough Dualling

A11 Roudham Heath - Attleborough Improvements

2. Data Collected

2.1   This Traffic Impact Study (TIS) for the A11 Roudham Heath - Attleborough Improvement Scheme included the following surveys.

'Before Surveys'

• 6 Highways Agency permanent Automatic Traffic Count sites (ATC), located on the A11;
• 8 Norfolk County Council sites;
• Journey Time Survey (JTS) undertaken on 30 May 2001, before the improvement scheme.

'After Surveys'

• The 'After' surveys mirror the 'Before' surveys, with an up-to-date Journey Time Survey undertaken on 29th April 2003.

2.2   The details of the 'Before' and 'After' surveys are described below.

AUTOMATIC TRAFFIC COUNTS (ATC)

2.3   The 'Before' study comprised surveys at fourteen Automatic Traffic Count (ATC) sites; the locations of which are described below. There were five HA Count Sites on the A11, and one on the A47, and two County sites on the A140, at the following locations:

• A11- Elveden;
• A11 - South of Thetford;
• A11 - South of the scheme at Roudham;
• A11 - Hargham, South of Attleborough, on the new improved section;
• A11 - North of Wymondham;
• A47 - North Tuddenham;
• A140 - North of Long Stratton (near B1135);
• A140 - South of Long Stratton.

A further six county sites were used on the surrounding minor roads. They were at the following locations:

• Harling Road;
• Northend Lane;
• Two at Heath Road;
• Hargham Road;
• London Road.

2.4   For the 'After' study, the ATC sites used for the 'Before' counts were repeated in order for changes in traffic flows to be identified.

JOURNEY TIME SURVEYS

2.5   'Before' surveys were undertaken on Wednesday 30th May 2001 and the 'After' surveys on Thursday 29th May 2003.

2.6   Journey Time (JT) surveys were undertaken on the A11, as identified in Figure 2.1 below. The survey runs started from the end of the dual carriageway at Roudham Heath and finished at the start of dual carriageway north of Attleborough. The surveys were undertaken over the morning (0800 - 0900 hours) and evening (1700 - 1800 hours) peak periods, as well as an inter-peak period (1000 - 1500 hours).

Figure 2.1 (1260KB PDF)