TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Gelling Agents: (III) comprises:(1) hydrogen bond donor(s) (D), preferably containing nitrogen, oxygen and/or sulfur as hydrogen carrying heteroatom, especially as an alcohol, thiol, phenol, primary or secondary amino, quaternary ammonium, amide, urea, hydrazine, carboxy, oxime, hydrazone and/or imine group);(2) hydrogen bond acceptor(s) (A), preferably containing phosphorus, nitrogen, oxygen and/or sulfur as electron pair carrying heteroatom, especially in a CO, PO, NO or PO group or as a linear or cyclic hydrocarbyl containing O, S, N and/or P in the chain, particularly as an alcohol, phenol, amide, ester, urea, hydrazine, acid, ketone, aldehyde, lactone, lactam, anhydride, imide, sulfoxide, sulfone, sulfonate, sulfate, sulfite, sulfonic acid, sulfide, ether, phosphine, phosphite, phosphonate, phosphate, nitrite and/or nitrate group; and(3) bitumen compatibilizer(s) (C), selected from at least 4C linear hydrocarbon chains, 3-8C cycloaliphatic rings and/or fused polycyclic cycloaliphatic, aliphatic-aromatic or aromatic ring systems in which each ring has 5-6C.(III) is in the form of a single compound, preferably containing units of formula R-(NH)nCONH-(X)m-NHCO(NH)n-R' (IIIA) or (R-NHCO)x-Z-(NHCO-R')y (IIIB).R, R' = optionally substituted, saturated or unsaturated, linear, branched or cyclic 1-22C hydrocarbon chain (optionally containing heteroatoms, rings and/or heterocycles);X = group containing a chain as defined for R;m, n = 0 or 1;Z = benzene-1,3,5-triyl, 1,3,5-triazine-2,4,6-triyl or N(pC6H4-)3;x, y = 0-3;x + y = 3.(III) (as a single compound) is particularly a sorbitol derivative. Alternatively (III) is a combination of two or more different compounds which jointly contain the (A), (D) and (C) moieties, especially a combination of an amine and a carboxylic acid, an aminopyridine and a barbituric acid derivative or a sulfosuccinate derivative and a phenol derivative. (III) have a molecular weight of 2000 or less (preferably 1000 or less). Preferred Composition: (I) contains (III) at 0.1-5 wt. % based on (II). (I) optionally also contain at least one polymer and/or flow agent. The bitumen (II) is selected from atmospheric or vacuum distillation residues, reduced viscosity residues and/or blown residues. SPECIFIC COMPOUNDS - Use of 8 single compounds (III) is disclosed, e.g. N,N'-ethylene-di-(stearamide) (C17H35CONH-CH2CH2-NHCOC17H35) (IIIa), 4,4'-bis-(dodecylamino-carbonylamino)-diphenyl methane, N,N',N''-tridecanoyl-melamine and 1,3:2,4-di-O-benzylidene-D-sorbitol. Also disclosed is use of 8 combinations of compounds (III), e.g. 5-octyl-2,4,6-triamino-pyrimidine plus 5,5-dioctyl-barbituric acid and 2-naphthol plus sodium dioctyl-sulfosuccinate.    EXAMPLE - The gelling agent N,N'-ethylene-di-(stearamide) (IIIa) was incorporated at 2% in a bitumen (IIa) (direct distillation type; grade 70-100; characteristics corresponding to the norm NF EN 12591) by stirring at 160-170 degrees C for 1 hour. On cooling, a homogeneous product (Ia) was obtained. (Ia) had needle penetration 5.8 mm at 25 degrees C, ball and ring softening point 91.0 degrees C, Pfeiffer penetrability index 6.1 and viscosity (Brookfield) 225 mPa.s at 140 degrees C or 145 mPa.s at 160 degrees C. The corresponding values for (IIa) (without addition of (IIIa)) were 7.6 mm, 46.6 degrees C, -1.0, 267 mPa.s and 165 mPa.s.