In Appendix 2 of the Dryden Road Equality Impact Assessment dated 27/02/2026, there is a projected figure of 3,900 vehicle movements a day on Dryden Road under ‘Option C: Reopen to two way vehicle traffic’. (‘Option C’ is ‘Option 3’ on the consultation)
1) Please can you show all data and workings which led to the calculation of this figure, and explain them in terms and calculations that a layperson might reasonably expect to understand.
| Two- Way flow | ||
| 1. | Identify the 2019 motorised vehicle flows on section of Dryden Road between Wonford House and Barrack Rd, as counted at junction of Barrrack Road and Dryden road | 6,000 |
| 2. | Identify the traffic flows on Dryden Road in 2019 that travelled straight ahead onto Wonford Road | 3,200 |
| 3. | Identify the traffic flows on Dryden Road in 2019 that travelled left or right onto Barrack Road | 2,800 |
| 4. | Identify a factor for the percentage of previous through trips that would not return to Dryden Road. | 67% |
| 5. | Identify the amount of ahead traffic expected not to return to Dryden Road = (2 * 4) | 2,100 |
| 6. | Identify a factor of all other trips on Dryden Road (left/right turn) that would not return to Dryden Road | 0% |
| 7. | Identify the amount of ahead traffic expected not to return to Dryden Road = (3 * 6) | 0 |
| 8. | Forecast future Dryden Road Flows = 1 – 5 – 7 = (6,000 – 2,100 – 0) | 3,900 |
2) What is the uncertainty associated with 3,900 vehicle movements, expressed either as a standard deviation or as a percentile interval?
Devon County Council does not hold this information as this has not been calculated.
3) What assumptions were made in coming to this figure?
As outlined above, the two key assumptions are that:
- 67% of Dryden Road to Wonford Road through traffic would not return.
- All of the previous traffic on Dryden Road (i.e. left/right turn to Barrack would return to pre filter levels).
4) What work was done to model projected traffic flows into the future? What were the projections, and over what time frame?
The forecast future flows have been calculated from the current and historic flows. No future traffic growth is assumed (consistent with flat traffic levels on radial routes in Exeter since 2000).
5) What are your projected five-day traffic flows for Dryden Road under Option C for one and five years into the future?
Devon County Council does not hold this information as this has not been calculated.
6) Is the 3,900 movements figure a projected seven-day (Mon-Sun) average or is it a projected workday (Mon-Fri) average? If the former, what would the projected workday (Mon-Fri) average be?
This represents a neutral weekday, as per the base count data.