That route could perhaps be tied in to the Murieston service providing additional links from Livingston South Station?
I would generally agree that Livingston - Whitburn could do with an improved 15 or 20 minute frequency, however with the X17, X18 and X27 that would be six buses per hour to Edinburgh which is a bit excessive. The main issue really being that almost all the links provided by the X17 are provided by other routes.
The X27 would be faster from Livingston to Edinburgh than the X17, so in terms of offering a faster route from Whitburn/Blackburn/Seafield to Edinburgh its probably better suited to take the more direct route via Livingston Village with the X17 going via Eliburn, since the X17 would only go to Deans it wouldn't matter as much if it takes a slower route after The Centre. Although as you say it would leave a gap within Howden, perhaps if the 276 were half hourly part route it could be revised to operate via Howden and Ladywell instead of Pumpherston which would be covered by the 275 anyway.
Of course, there are all just hypothetical ideas based on "ideal circumstances" which are unlikely to exist at least in the short term.
In reality the priority just now is without a doubt to cover the key links and offer the best level of service possible with the resources available. For example in the long term i'd be surprised if the 72 continues to serve Fauldhouse, they've likely only done that just now because it gives Fauldhouse two buses per hour while using the least number of resources possible as the 72 if it didn't extend to Fauldhouse would otherwise have excessive layover. Likewise the 73 to me clearly seems like more of a temporary solution. As someone else pointed out on another thread the network seems to have been designed with the upcoming replacement tenders for the Shotts and Armadale services in mind.
If Lothian do get those tenders i'll certainly be grabbing the popcorn and awaiting the tweets from certain individuals from another company...
So I broke it down slightly again. I looked further into the X17 and X27 journey times and found that they were overall pretty similar, but definitely not the same. I was keen to keep what I had in Howden and that probably meant it was just going to be easier to stick with what I had originally in that part. The X17 and 281 have been slightly changed in Whitburn so as to offer a link to the J4 Distribution Centre from the West End.
Anyway here’s how it looks now with a new 285 added and also the 276 renumbered to 270. An Airport bound 250 has also been added:
Bold/Italic - Peak Time Extension/Certain Journeys Only
X17: Fauldhouse - Eastfield Road - Longridge - Whitburn Cross - Shanks Road - East Whitburn - Blackburn - Seafield - Livingston Village - St John’s Hospital - West Lothian College - The Centre - Craigshill - Fastlink - Deer Park - Uphall - Broxburn -
RBS Gogarburn - Edinburgh
Half hourly service with double decks. Frequency combined with
X18 to offer an every 15 minutes between Uphall, Broxburn and Edinburgh.
X18: Rigghouse Road - Whitburn - Whitburn Cross - Shanks Road - Armadale - Bathgate - Boghall - Tesco Distribution Centre - Dechmont - Uphall - Broxburn -
RBS Gogarburn - Edinburgh
Half hourly service with double decks. Frequency combined with
X17 to offer an every 15 minutes service between Uphall, Broxburn and Edinburgh.
X27: Rigghouse Road - Whitburn - East Whitburn - Whitburn Cross - Blackburn (Ash Grove) - Seafield - Eliburn - Ladywell East (W) - St John’s Hospital - Howden East - The Centre - Dedridge North - Dedridge West - Dedridge East - Main Street - Mid Calder - Calderwood - Camps - Wilkieston - Hermiston P&R - Edinburgh
Half hourly service with double decks. Frequency combined with
X28 to offer an every 15 minutes service between Livingston and Edinburgh.
X28: Morrisons - Bathgate - Boghall - Tesco Distribution Centre - Deans North - Knightsridge West - Knightsridge East - Ladywell East (E) - St John’s Hospital - Craigshill East - The Centre - Dedridge East - Calder Park Road - Mid Calder - East Calder - Kirknewton - Hermiston P&R - Edinburgh
Half hourly service with double decks. Frequency combined with
285 to offer an every 15 minutes service between Deans and Livingston. Frequency also combined with
X27 to offer an every 15 minutes service between Livingston and Edinburgh.
X40: St John’s Hospital - West Lothian College - The Centre - ASDA - Calder Park Road - Mid Calder - Calderwood - Camps - Wilkieston - Hermiston P&R - Westside Plaza - Clovenstone - Gilmerton - Royal Infirmary
Hourly service with double decks.
250: The Centre - Fastlink - Deer Park - Uphall - Broxburn - Winchburgh - Kirklands Park - Kirkliston - Ingliston P&R - Edinburgh Airport
Half hourly 24/7 service with single decks.
270: Livingston South Station - Murieston West - Murieston East - Murieston - Bellsquarry - Dedridge North - The Centre - ASDA - Howden South - St John’s Hospital - Ladywell East (E) - Pumpherston - Uphall Station - Uphall - Broxburn - Winchburgh School Campus - Winchburgh - Kirkliston - Ferrymuir Tesco - Echline Corner - High Street - Scotstoun
Half hourly service with single decks.
275: Boghall Estate - Boghall - Bathgate Station - Bathgate - Morrisons - Wester Inch - Blackburn - Seafield - Sky TV - Simpson Parkway - Rosebank Roundabout - Kirkton South - The Centre - Craigshill - Grange Road - Pumpherston - Uphall Station - Uphall - Broxburn - Newbridge - Gyle Centre - Edinburgh Park Station - Hermiston Gait - Edinburgh College (Sighthill) - Hermiston P&R - Research Park - Heriot-Watt University
Half hourly service with single decks.
280: Blackridge - Armadale - Lower Bathville - Bathgate - Boghall - Tesco Distribution Centre - Deans South - Carmondean Centre - Ladywell East (W) - St John’s Hospital - West Lothian College - The Centre - Dedridge North - Polbeth - West Calder - Loganlea - Addiewell - Stoneyburn - Bents - Fauldhouse
Half hourly service with double decks. Frequency combined with
281 to offer an every 15 minutes service between Bathgate and Livingston. Frequency also combined with
285 to offer an every 15 minutes service between Livingston and Loganlea.
281: Fauldhouse - Longridge - Dixon Terrace - Whitburn - Whitburn Cross - East Whitburn - M8 Junction 4 Distribution Centre - Birniehill - Morrisons - Bathgate - Boghall - Tesco Distribution Centre - Deans North - Ladywell East (W) - St John’s Hospital - Howden South - ASDA - The Centre
- Kirkton South - Rosebank Roundabout - Simpson Parkway - Sky TV
Half hourly service with single decks. Frequency combined with
280 to offer an every 15 minutes service between Bathgate and Livingston.
285: Deans North/Nellburn Roundabout - Deans South - Deans North - Carmondean Centre - Knightsridge - Ladywell West - Ladywell East (W) - St John’s Hospital - Howden East - ASDA - The Centre - Dedridge West - Polbeth - West Calder - Loganlea - Addiewell - Blackburn - Ash Grove - Boghall - Bathgate - Morrisons
Half hourly service with single decks. Frequency combined with
X28 to offer an every 15 minutes service between Deans and Livingston. Frequency also combined with
280 to offer an every 15 minutes service between Livingston and Loganlea.