I aplogize for not seeing this forum topic sooner. I was busy doing non-Trainz stuff. I've been working on an extensive music project with my piano teacher, which requires many, many hours away from Trainz.
Anyway, some of the Jointed Rail tracks will fill in underneath which will help. It's not procedural, but it should work for you in those locations.
For some nice embankment splines, if you are interested, check out these by jim_spb.
<kuid:211147:67009> j_embankment GG_2_BNS_Grass mesh library
<kuid:211147:37121> j_embankment GGL1_2_GS 1/1.5 0-5m 1t
<kuid:211147:37123> j_embankment GGL1_YS 1/1.5 0-5m 1t
<kuid:211147:67011> j_embankment GGL1_2_GS mesh library
<kuid:211147:67012> j_embankment GGL1_LBS2 mesh library
<kuid:211147:37124> j_embankment GGL1_2_YS 1/1.5 0-5m 1t
<kuid:211147:67014> j_embankment GGL1_2_YS mesh library
<kuid:211147:37126> j_embankment GGL1_2_YS_Grass 1/1.5 0-5m 1t
<kuid:211147:67006> j_embankment GG_YS_Grass mesh library
<kuid:211147:37118> j_embankment GGL1_2_YS_Grass 1/1 0-5m 1t
<kuid:211147:67016> j_embankment GGL1_2_YS_Grass mesh library
<kuid:211147:67007> j_embankment GG_2_YS_Grass mesh library
<kuid:211147:37119> j_embankment GGL1_BNS_Grass 1/1 0-5m 1t
<kuid:211147:67015> j_embankment GGL1_YS_Grass mesh library
<kuid:211147:37127> j_embankment GGL1_BNS_Grass 1/1.5 0-5m 1t
<kuid:211147:67017> j_embankment GGL1_BNS_Grass mesh library
<kuid:211147:67008> j_embankment GG_BNS_Grass mesh library
<kuid:211147:37120> j_embankment GGL1_GS 1/1.5 0-5m 1t
<kuid:211147:37122> j_embankment GGL1_LBS2 1/1.5 0-5m 1t
<kuid:211147:67010> j_embankment GGL1_GS mesh library
<kuid:211147:37125> j_embankment GGL1_YS_Grass 1/1.5 0-5m 1t
<kuid:211147:67013> j_embankment GGL1_YS mesh library
<kuid:211147:67005> j_embankment GG_2_YS mesh library
<kuid:211147:37117> j_embankment GGL1_YS_Grass 1/1 0-5m 1t
<kuid:211147:67001> j_embankment GG_GS mesh library
<kuid:211147:37113> j_embankment GGL1_2_GS 1/1 0-5m 1t
<kuid2:211147:37022:1> j_embankment GGL1_2_GS 1/1 5m 1t
<kuid:211147:67004> j_embankment GG_YS mesh library
<kuid:211147:37116> j_embankment GGL1_2_YS 1/1 0-5m 1t
<kuid2:211147:37087:1> j_embankment GG_LBS 1/1 5m 1t
<kuid2:211147:37023:1> j_embankment GGL1_2_YS 1/1 5m 1t
<kuid2:211147:37088:1> j_embankment GG_YS 1/1 5m 1t
<kuid2:211147:37024:1> j_embankment GGL1_2_YS_Grass 1/1 5m 1t
<kuid2:211147:37089:1> j_embankment GG_2_YS 1/1 5m 1t
<kuid2:211147:37025:1> j_embankment GGL1_BNS_Grass 1/1 5m 1t
<kuid:211147:37112> j_embankment GGL1_GS 1/1 0-5m 1t
<kuid2:211147:37090:1> j_embankment GG_YS_Grass 1/1 5m 1t
<kuid2:211147:37026:1> j_embankment GGL1_GS 1/1 5m 1t
<kuid:211147:67002> j_embankment GG_2_GS mesh library
<kuid:211147:37114> j_embankment GGL1_LBS2 1/1 0-5m 1t
<kuid2:211147:37004:1> j_embankment GGL1_LBS2 1/1 5m 1t
<kuid:211147:67003> j_embankment GG_LBS mesh library
<kuid:211147:37115> j_embankment GGL1_YS 1/1 0-5m 1t
<kuid2:211147:37027:1> j_embankment GGL1_YS 1/1 5m 1t
<kuid2:211147:37092:1> j_embankment GG_BNS_Grass 1/1 5m 1t
<kuid2:211147:37028:1> j_embankment GGL1_YS_Grass 1/1 5m 1t
<kuid:211147:37102> j_embankment GG_2_BNS_Grass 1/1 0-5m 1t
<kuid2:211147:37093:1> j_embankment GG_2_BNS_Grass 1/1 5m 1t
<kuid:211147:37111> j_embankment GG_2_BNS_Grass 1/1.5 0-5m 1t
<kuid:211147:37098> j_embankment GG_2_YS 1/1 0-5m 1t
<kuid:211147:37107> j_embankment GG_2_YS 1/1.5 0-5m 1t
<kuid2:211147:37109:1> j_embankment GG_2_YS_Grass 1/1.5 0-5m 1t
<kuid:211147:37101> j_embankment GG_BNS_Grass 1/1 0-5m 1t
<kuid:211147:37110> j_embankment GG_BNS_Grass 1/1.5 0-5m 1t
<kuid:211147:37094> j_embankment GG_GS 1/1 0-5m 1t
<kuid2:211147:37085:1> j_embankment GG_GS 1/1 5m 1t
<kuid:211147:37103> j_embankment GG_GS 1/1.5 0-5m 1t
<kuid:211147:37096> j_embankment GG_LBS 1/1 0-5m 1t
<kuid:211147:37105> j_embankment GG_LBS 1/1.5 0-5m 1t
<kuid:211147:37097> j_embankment GG_YS 1/1 0-5m 1t
<kuid:211147:37106> j_embankment GG_YS 1/1.5 0-5m 1t
<kuid:211147:37099> j_embankment GG_YS_Grass 1/1 0-5m 1t
<kuid:211147:37108> j_embankment GG_YS_Grass 1/1.5 0-5m 1t
<kuid:211147:37095> j_embankment GG_2_GS 1/1 0-5m 1t
<kuid2:211147:37086:2> j_embankment GG_2_GS 1/1 5m 1t
<kuid:211147:37104> j_embankment GG_2_GS 1/1.5 0-5m 1t
<kuid:211147:37100> j_embankment GG_2_YS_Grass 1/1 0-5m 1t
<kuid2:211147:37091:2> j_embankment GG_2_YS_Grass 1/1 5m 1t