Is there really that much of a need for capacity improvements in the Birmingham area? Aside during disruption whenever I see local trains in the morning and evening peak they aren't that crowded. Looking at the ''finding a seat'' page on the LM website, services aren't that busy, and those that are even out after just a few minutes into the journey.
The Snow Hill lines don't have ''finding a seat'' chart online, but anecdotal evidence would say that crowding here isn't that bad.
Those services that are busy tend to be the longer distance services IME.
Some of the Cross City and Snow Hill lines services can get very cosy at peak times with full and standing being the norm, though not normally to the extent of crush loaded conditions.
For instance, at 2009 passenger levels, 377 passengers alighted at New Street from the 08:03 Lichfield City to Longbridge, which at the time was a 3-car 323 intended to seat 289. In the evening peak, there were 405 passengers boarding the 16:17 Lichfield Trent Valley to Redditch, again a single 3-car 323, and 388 and 396 on the 16:47 Lichfield Trent Valley to Redditch and 16:54 Four Oaks to Longbridge respectively, both 6-car services. And these figures fail to take into account those passengers travelling through New Street on these trains from Cross City north to Cross City south.
On the Snow Hill lines, once again using 2009 figures, 283 passengers were counted alighting at Snow Hill from the 07:33 Worcester Foregate Street to Dorridge and 229 from the 07:47 Leamington Spa to Worcester Foregate Street (Following on from 117 passengers alighting at Moor Street). Both these services were 5-carriage 150 formations. 205 alighted at Snow Hill from the 08:10 Kidderminster to Marylebone service, and 213 from the 08:14 Stourbridge Junction to Shirley, the former a four car Chiltern 168, the latter a 4-car 150.
In the evening peak, 242 passengers boarded the 16:55 Stourbridge Junction to Stratford upon Avon at Snow Hill, a 3-car 150, and a further 65 at Moor Street.
For reference, a 3-car hybrid 150 seats 212 passengers, and a 2-car 150 unit 141.