The Dunstable scheme was never going to get off the ground after about 1995....
In 1995 there were FOUR ideas for the route, bus, Thameslink, tram and a rail shuttle service (a bit like Stourbridge got, but with bigger vehicles). The council were only ever interested in the bus scheme, but even then the bus scheme had more stops on it than the current plan.
....The increase in services on Thameslink have taken all the spare capacity and to get from the old Dunstable line onto the MML 'slows' (which are the eastern pair of tracks) would either have meant having to cross the fasts or involved expensive flyovers....
Semi-fast southbound Thameslink services at the time joined the fast line at Radlett generally and only two of the four semi-fast northbound services went as far as Luton (to Leagrave Junction) and only if they were on time.
The branch would probably have had to join the fast lines as there really is no room for a flyover, but I doubt capacity issues were as bad as that at the time, although I have no definitive proof of that.
....Additionally, the Dunstable line had limited capacity - I believe it was only ever single track (happy to be corrected if I'm wrong) so the best that could be achieved was IIRC a half-hourly service....
I only remember it being single track but then I only remember it after the relief road was built right next to it, there was/is space in places for loops and double track to be installed though.
....And the site of Bute St had been sold to the university who have built accommodation on it and at least one bridge has been removed....
Possibly some of the track bed was, but the station was where the carpark is behind the bus station AFAIAA.
....Dunstable, unlike St Ives, also has decent connections to other, existing railway stations - Leagrave is on the Luton / Dunstable border, Luton, Luton Airport Parkway and you could also argue Leighton Buzzard is easily accessible allowing the WCML to be used....
I lived within 15 minutes walk of Leagrave for the best part of 25 years, I don't recall any bus routes from Dunstable to Leagrave station, there was no bus stop at the station when I was last there 5 or so years ago (I do recall the 5 and another route (15?) went from Luton to the vague vicinity of Leagrave station).
There was one bus per hour to Leighton Buzzard each hour (I can't recall if it was the 61, 69 or 70), not that that was part of the scheme at any time that I know of.
I can recall buses to the airport being either 31, X31, 37 (via Houghton Regis) or 38 (also via Houghton Regis), but only ever one of the routes at any given time (not sure of any buses to Luton Parkway though).
I also recall buses to Luton Station being 31 or X31 only.
....Dunstable though, I couldn't see any practical alternative.
Tram was considered for a few years, but rejected, partly on cost grounds and mostly because it was required to go on normal roads that were already busy at certain points (namely in Luton town centre and Dunstable town centre :roll

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But, to be completely honest, I wouldn't be half as against the bus scheme, if there were actually useful stops on the route, like Dallow Road and the L&D which were both on the original plans for all four ideas (and perhaps even Kenilworth Road).