TC8 (Out) @ SH28 (2795)
TC9 (In) @ Nearest ETL

via these unpunctuated clues only

2895299492299131943131953196959433349434349494?

34953497349999999930299829982998289826259999

Route Checks. Count how many times you change from road colour to road colour and enter as follows:
1) White to Yellow
2) White to Red
3) Yellow to White
4) Yellow to Orange
5) Yellow to Red
6) Red to White
7) Red to Yellow
8) Red to Orange
9) Orange to Yellow
10) Orange to White

This was a swine to mark because of various interpretations and shortest route considerations. See the Competitors' Comments for some of the finer detail.

You should have decoded the numbers into a series of grid squares and grid lines. The requirement was to visit white roads either wholly contained in a GS or using ones that crossed GLs thus:

2895   2994   92     2991   31   94   31   31    95   31   96   95   94   33    34   94   34   34   94   94?   3495   34   97   34   99   99   99   99   30   2998    2998   2998   2898   26    2599   99

The road colour sequence you should have used went like this:

RYW(2895)YW(2994)YW(92)YW(2991)RYW(31)(94)YW(31)(31)(95)(31)(96)YR
YW(95)(94)YW(33)YW(34)(34)(94)(34)RW(94)(94?)RW(3495)RYW(34)(97)(34)YO
YW(99)YRW(99)(99)(99)YROW(30)YRW(2998)YW(2998)RW(2998)YW(2898)YO
RYW(26)YRW(2599)YRYW(99)Y

Of course, if you went wrong somewhere it was likely to penalise several route check answers - but that was how it was designed!

The Route Check answers were;
1) 17  2) 5  3) 15  4) 2  5) 6  6) 6  7) 6  8) 1   9) 1  10) 1